 Section 12 of an essay concerning humane understanding by John Locke, Book 4 of Knowledge and Powerability. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. 1. Knowledge of the existence of other finite beings is to be had only by actual sensation. The knowledge of our own being we have by intuition. The existence of a God reason clearly makes known to us as has been shown. The knowledge of the existence of any other thing we can have only by sensation, for there being no necessary connection of real existence with any idea a man hath in his memory, nor of any other existence but that of God with the existence of any particular man. No particular man can know the existence of any other being but only when by actual operating upon him it makes itself perceived by him. 4. The having the idea of anything in our mind no more proves the existence of that thing than the picture of a man evidences his being in the world or the visions of a dream make thereby a true history. 2. Instance. Whiteness of this paper. It is therefore the actual receiving of ideas from without that gives us notice of the existence of other things, and makes us know that something doth exist at that time without us, which causes that idea in us, though perhaps we neither know nor consider how it does it. 3. For it takes not from the certainty of our senses and the ideas we receive by them, that we know not the manner wherein they are produced. Whilst I write this, I have, by the paper affecting my eyes, that idea produced in my mind which, whatever object causes, I call white, by which I know that that quality or accident, i.e. whose appearance before my eyes always causes that idea, doth really exist and hath a being without me. 4. And of this, the greatest assurance I can possibly have, and to which my faculties can attain, is the testimony of my eyes, which are the proper and sole judges of this thing, whose testimony I have reason to rely on as so certain, that I can no more doubt, whilst I write this, that I see white and black, and that something really exists that causes that sensation in me, then that I write or move my hand, which is a certainty as great as human nature is capable of, concerning the existence of anything, but a man's self alone, and of God. 3. This notice by our senses, though not so certain as demonstration, yet may be called knowledge, and proves the existence of things without us. 4. The notice we have by our senses of the existing of things without us, though it be not altogether so certain as our intuitive knowledge, or the deductions of our reason employed about the clear abstract ideas of our own minds, yet it is an assurance that deserves the name of knowledge. 5. If we persuade ourselves that our faculties act and inform us right concerning the existence of those objects that affect them, it cannot pass from ill-grounded confidence, for I think nobody can, in earnest, be so skeptical as to be uncertain of the existence of those things which he sees and feels. 6. At least he that can doubt so far, whatever he may have with his own thoughts, will never have any controversy with me, since he never can be sure I say anything contrary to his own opinion. 7. As to myself, I think God has given me assurance enough of the existence of things without me, since, by their different application, I can produce in myself both pleasure and pain, which is one great concernment of my present state. 8. This is certain. The confidence that our faculties do not hear in deceive us is the greatest assurance we are capable of concerning the existence of material beings, for we cannot act anything but by our faculties, nor talk of knowledge itself, but by the help of those faculties which are fitted to apprehend even what knowledge is. 9. But besides the assurance we have from our senses themselves, that they do not err in the information they give us of the existence of things without us when they are affected by them, we are further confirmed in this assurance by other concurrent reasons. 4. One. Confirmed by concurrent reasons. First, because we cannot have ideas of sensation but by the inlet of the senses. It is plain those perceptions are produced in us by exterior causes affecting our senses, because those that want the organs of any sense never can have the ideas belonging to that sense produced in their minds. 5. This is too evident to be doubted, and therefore we cannot but be assured that they come in by the organs of that sense, and no other way. The organs themselves, it is plain, do not produce them, for then the eyes of a man in the dark would produce colours, and his nose smell roses in the winter. But we see nobody gets the relish of a pineapple till he goes to the indies where it is and tastes it. 5. Two. Secondly, because we find that an idea from actual sensation and another from memory are very distinct perceptions. 6. Because sometimes I find that I cannot avoid the having those ideas produced in my mind. For though when my eyes are shut or windows fast, I cannot pleasure recall to my mind the ideas of light or the sun which former sensations had lodged in my memory. So I cannot pleasure lay by that idea and take into my view that of the smell of a rose or taste of sugar. But if I turn my eyes at noon towards the sun, I cannot avoid the ideas which the light or sun then produces in me, so that there is a manifest difference between the ideas laid up in my memory over which, if they were there only, I should have constantly the same power to dispose of them and lay them by at pleasure. And those which force themselves upon me, and I cannot avoid having. And therefore it must needs be some exterior cause and the brisk acting of some objects without me whose efficacy I cannot resist that produces those ideas in my mind whether I will or know. Besides, there is nobody who does not perceive the difference in himself between contemplating the sun as he hath the idea of it in his memory and actually looking upon it, of which too his perception is so distinct that few of his ideas are more distinguishable one from another. And therefore he have certain knowledge that they are not both memory or the actions of his mind and fancies only within him, but that actual seeing hath a cause without. 6. 3. Thirdly, because pleasure or pain which accompanies actual sensation accompanies not the returning of those ideas without the external objects. Add to this that many of those ideas are produced in us with pain which afterwards we remember without the least offence. Thus the pain of heat or cold when the idea of it is revived in our minds gives us no disturbance which when felt was very troublesome and is again when actually repeated which is occasioned by the disorder the external object causes in our bodies when applied to them. And we remember the pains of hunger, thirst or the headache without any pain at all which would either never disturb us or else constantly do it as often as we thought of it, were there nothing more but ideas floating in our minds and appearances entertaining our fancies without the real existence of things affecting us from abroad. The same may be said of pleasure, accompanying several actual sensations, and though mathematical demonstration depends not upon sense yet the examining them by diagrams gives great credit to the evidence of our sight and seems to give it a certainty approaching to that of demonstration itself. 4. It would be very strange that a man should allow it for an undeniable truth that two angles of a figure which he measures by lines and angles of a diagram should be bigger one than the other, and yet doubt of the existence of those lines and angles which by looking on he makes use of to measure that by. 7. Four. Fourthly, because our senses assist one another's testimony of the existence of outward things and enable us to predict. Our senses in many cases bear witness to the truth of each other's report concerning the existence of sensible things without us. He that sees a fire may, if he doubt whether it be anything more than a bear fancy, feel it too and be convinced by putting his hand in it, which certainly could never be put into such exquisite pain by a bear idea or phantom, unless that the pain be a fancy too, which yet he cannot, when the burn is well by raising the idea of it, bring upon himself again. Thus I see, whilst I write this, I can change the appearance of the paper, and by designing the letters tell beforehand what new idea it shall exhibit the very next moment by barely drawing my pen over it, which will neither appear, let me fancy as much as I will if my hands stand still, although I move my pen if my eyes be shut. Nor, when those characters are once made on the paper, can I choose afterwards but see them as they are, that is, have the ideas of such letters as I have made. Whence it is manifest that they are not barely the sport and play of my own imagination, when I find that the characters that were made at the pleasure of my own thoughts do not obey them, nor yet cease to be, whenever I shall fancy it, but continue to affect my senses constantly and regularly according to the figures I made them. To which, if we will add, that the sight of those shall from another man draw such sounds as I beforehand design they shall stand for, there will be little reason left to doubt that those words I write do really exist without me, when they cause a long series of regular sounds to affect my ears, which could not be the effect of my imagination, nor could my memory retain them in that order. 8. This certainty is as great as our condition needs. But yet, if after all this anyone will be so skeptical as to distrust his senses and to affirm that we all see and hear, feel and taste, think and do, during our whole being, is but the series and deluding appearances of a long dream, whereof there is no reality, and therefore will question the existence of all things or our knowledge of anything, I must desire him to consider that, if all be a dream, then he doth but dream that he makes the question, and so it is not much matter that a waking man should answer him. But yet, if he pleases, he may dream that I make him this answer, that the certainty of things existing in Rerum Natura, when we have the testimony of our senses for it, is not only as great as our frame can attain to, but as our condition needs. For our faculties being suited not to the full extent of being, nor to a perfect clear, comprehensive knowledge of things free from all doubt and scruple, but to the preservation of us in whom they are, and accommodated to the use of life. They serve to our purpose well enough if they will but give us certain notice of these things which are convenient or inconvenient to us. For he that sees a candle burning, and hath experimented the force of its flame by putting his finger in it, will little doubt that this is something existing without him, which does him harm and puts him to great pain, which is assurance enough when no man requires greater certainty to govern his actions by than what is as certain as his actions themselves. And if our dreamer pleases to try whether the glowing heat of a glass furnace be barely a wandering imagination in a drowsy man's fancy, by putting his hand into it, he may perhaps be wicked into a certainty greater than he could wish, that it is something more than bare imagination, so that this evidence is as great as we can desire, being as certain to us as our pleasure or pain, i.e. happiness or misery, beyond which we have no concernment either of knowing or being. Such an assurance of the existence of things without us is sufficient to direct in us the attaining the good and avoiding the evil which is caused by them, which is the important concernment we have of being made acquainted with them. 9. But reaches no further than actual sensation In fine then, when our senses do actually convey into our understandings any idea, we cannot but be satisfied that there doth something at that time really exist without us, which doth affect our senses, and by them give notice of itself to our apprehensive faculties, and actually produce that idea which we then perceive. And we cannot so far distrust their testimony, as to doubt that such collections of simple ideas as we have observed by our senses to be united together, do really exist together. But this knowledge extends as far as the present testimony of our senses, employed about particular objects that do then affect them, and no further. For if I saw such a collection of simple ideas, as is want to be called man, existing together one minute since, and am now alone, I cannot be certain that the same man exists now, since there is no necessary connection of his existence a minute since with his existence now. By a thousand ways he may cease to be, since I had the testimony of my senses for his existence. And if I cannot be certain that the man I saw last today is now in being, I can less be certain than he is so, who have been longer removed from my senses, and I have not seen since yesterday, or since the last year, and much less can I be certain of the existence of men that I never saw, and therefore, though it be highly probable that millions of men do now exist, yet whilst I am alone writing this, I have not that certainty of it which we strictly call knowledge. Though the great likelihood of it puts me past doubt, and it be reasonable for me to do several things upon the confidence that there are men, and men also of my acquaintance, with whom I have to do, now in the world. But this is but probability, not knowledge. 10. Folly to expect demonstration in everything Whereby yet we may observe how foolish and vain a thing it is for a man of narrow knowledge, who having reason given him to judge of the different evidence and probability of things, and to be swayed accordingly. How vain, I say, it is to expect demonstration and certainty in things not capable of it, and refuse assent to very rational propositions, and act contrary to very plain and clear truths, because they cannot be made out so evident as to surmount every the least, I will not say reason, but pretense of doubting. He that, in the ordinary affairs of life, would admit of nothing but direct plain demonstration, would be sure of nothing in this world, but of perishing quickly. The wholesomeness of his meat or drink would not give him reason to venture on it, and I would faint know what it is he could do upon such grounds as are capable of no doubt, no objection. 11. Past existence of other things is known by memory As when our senses are actually employed about any object, we do know that it does exist, so by our memory we may be assured that here too four things that affected our senses have existed, and thus we have knowledge of the past existence of several things, whereof our senses having informed us, our memories still retain the ideas, and of this we are passed all doubt, so long as we remember well. But this knowledge also reaches no further than our senses have formally assured us. Thus, seeing water at this instant, it is an unquestionable truth to me that water doth exist, and remembering that I saw it yesterday, it will also be always true, and as long as my memory retains it always an undoubted proposition to me that water did exist the 10th of July 1688, as it will also be equally true that a certain number of very fine colours did exist, which at the same time I saw upon a bubble of that water. But being now quite out of sight both of the water and bubbles too, it is no more certainly known to me that the water doth now exist than that the bubbles or colours therein do so. It being no more necessary that water should exist today, because it existed yesterday, than that the colours or bubbles exist today, because they existed yesterday, though it be exceedingly much more probable, because water have been observed to continue long in existence, but bubbles and the colours on them quickly cease to be. 12. The existence of other finite spirits not knowable and rests on faith What ideas we have of spirits and how we come by them I have already shown, but though we have those ideas in our minds and know we have them there, the having the ideas of spirits does not make us know that any such things do exist without us, or that there are any finite spirits or any other spiritual beings but the eternal God. We have ground from revelation and several other reasons to believe with assurance that there are such creatures, but our senses not being able to discover them we want the means of knowing their particular existences. For we can no more know that there are finite spirits really existing by the idea we have of such beings in our minds than by the ideas anyone has of fairies or centaurs. He can come to know that things answering those ideas do really exist. And therefore concerning the existence of finite spirits, as well as several other things, we must content ourselves with the evidence of faith, but universal certain propositions concerning this matter are beyond our reach. For however true it may be, BG, that all the intelligent spirits that God ever created do still exist, yet it can never make a part of our certain knowledge. These and the like propositions we may ascent to as highly probable, but are not, I fear, in this state capable of knowing. We are not, then, to put others upon demonstrating, nor ourselves upon search of universal certainty in all those matters, wherein we are not capable of any other knowledge, but what our senses give us in this or that particular. Only particular propositions concerning concrete existences are knowable. By which it appears that there are two sorts of propositions. One, there is one sort of propositions concerning the existence of anything answerable to such an idea, as having the idea of an elephant, phoenix, motion or an angel, in my mind, the first and natural inquiry is, whether such a thing does anywhere exist, and this knowledge is only of particulars. No existence of anything without us, but only God, can certainly be known further than our senses inform us. Two, there is another sort of propositions, wherein is expressed the agreement or disagreement of our abstract ideas and their dependence on one another. Such propositions may be universal and certain. So, having the idea of God and myself, of fear and obedience, I cannot but be sure that God is to be feared and obeyed by me, and this proposition will be certain concerning man in general, if I have made an abstract idea of such a species, whereof I am one particular. Yet this proposition, how certain so ever that men ought to fear and obey God, proves not to me the existence of men in the world, but will be true of all such creatures whenever they do exist, which certainty of such general propositions depends on the agreement or disagreement to be discovered in those abstract ideas. Fourteen, and all general propositions that are known to be true concern abstract ideas. In the former case, our knowledge is the consequence of the existence of things, producing ideas in our minds by our senses. In the latter, knowledge is the consequence of the ideas, be they what they will, that are in our minds, producing their general certain propositions. Many of these are called Eternity Veritates, and all of them indeed are so, not from being written, all or any of them, in the minds of all men, or that they were any of them propositions in any one's mind, till he, having got the abstract ideas, joined or separated them by affirmation or negation. But where so ever we can suppose such a creature as man is, endowed with such faculties, and thereby furnished with such ideas as we have, we must conclude, he must needs, when he applies his thought to the consideration of his ideas, know the truth of certain propositions that will arise from the agreement or disagreement which he will perceive in his own ideas. Such propositions are therefore called eternal truths, not because they are eternal propositions actually formed, and antecedent to the understanding that at any time makes them, nor because they are imprinted on the mind from any patterns that are anywhere out of the mind, and existed before. But because, being once made about abstract ideas, so as to be true, they will, whenever they can be supposed to be made again at any time, past or come, by a mind having those ideas, always actually be true. For names being supposed to stand perpetually for the same ideas, and the same ideas having immutably the same habitudes one to another, propositions concerning any abstract ideas that are once true must needs be eternal verities. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. CHAPTER 12 OF THE IMPROVEMENT OF OUR KNOWLEDGE Knowledge is not got from maxims. It having been the common received opinion amongst men of letters, that maxims were the foundation of all knowledge, and that the sciences were each of them built upon certain precognita, from whence the understanding was to take its rise, and by which it was to conduct itself in its inquiries into the matters belonging to that science. The beaten road of the schools has been to lay down in the beginning one or more general propositions as foundations were on to build the knowledge that was to be had of that subject. These doctrines, thus laid down for foundations of any science, were called principles, as the beginnings from which we must set out, and look no further backwards in our inquiries, as we have already observed. 2. THE OCCASION OF THAT OPINION One thing which might probably give an occasion to this way of preceding in other sciences was, as I suppose, the good success it seemed to have in mathematics, where in men, being observed to attain a great certainty of knowledge, these sciences came by preeminence to be called mathemata, and mathesis, learning, or things learned, thoroughly learned, as having, of all others, the greatest certainty, clearness and evidence in them. 3. BUT FROM COMPARING CLEAR AND DESTINCED IDEAS But if any one will consider, he will, I guess, find, that the great advancement and certainty of real knowledge, which men arrived to in these sciences, was not owing to the influence of these principles, nor derived from any peculiar advantage they received from two or three general maxims, laid down in the beginning, but from the clear, distinct, complete ideas their thoughts were employed about, and the relation of equality and excess so clear between some of them, that they had an intuitive knowledge, and by that a way to discover it in others, and this without the help of those maxims. 4. For I ask, is it not possible for a young lad to know that his whole body is bigger than his little finger, but by virtue of this axiom, that the whole is bigger than a part, nor be assured of it, till he has learned that maxim? 5. Or cannot a country wench know that, having received a shilling from one that owes her three, and a shilling also from another that owes her three, the remaining debts in each of their hands are equal? 6. Cannot she know this, I say, unless she fetch the certainty of it from this maxim, that, if you take equals from equals, the remainder will be equals, a maxim which possibly she never heard or thought of? 7. I desire any one to consider, from what has been elsewhere said, which is known first and clearest by most people, the particular instance or the general rule, and which it is that gives life and birth to the other. 8. These general rules are but comparing our more general and abstract ideas, which are the workmanship of the mind, made, and names given to them for the easier dispatch in its reasonings, and drawing into comprehensive terms and short rules its various and multiplied observations. 9. But knowledge began in the mind, and was founded on particulars, though afterwards perhaps no notice was taken thereof. It being natural for the mind, forward still to enlarge its knowledge, most attentively to lay up those general notions, and make proper use of them, which is to disburden the memory of the cumbersome load of particulars. 10. For I desire it may be considered, what more certainty there is to a child, or any one, that his body, little finger and all, is bigger than his little finger alone, after you have given to his body the name whole and to his little finger the name part, than he could have had before, or what new knowledge concerning his body can these two relative terms give him which he could not have without them. 11. Could he not know that his body was bigger than his little finger, if his language were yet so imperfect that he had no such relative terms as whole and part? I ask further, when he has got these names, how is he more certain that his body is a whole and his little finger a part, than he was or might be certain before he learnt those terms, that his body was bigger than his little finger? 12. Anyone may as reasonably doubt or deny that his little finger is a part of his body, as that it is less than his body, and he that can doubt whether it be less, will as certainly doubt whether it be a part, so that the maxim, the whole is bigger than a part, can never be made use of to prove the little finger less than the body, but when it is useless, by being brought to convince one of a truth which he knows already. 13. For he that does not certainly know that any parcel of matter, with another parcel of matter joined to it, is bigger than either of them alone, will never be able to know it by help of these two relative terms, whole and part, make of them what maxim you please. 4. Dangerous to build upon precarious principles But be it in the mathematics as it will, whether it be clearer that, taking an inch from a black line of two inches and an inch from a red line of two inches, the remaining parts of the two lines will be equal, or that, if you take equals from equals the remainder will be equals, 5. Which, I say, of these two is the clearest and first known, I leave to any one to determine, it not being material to my present occasion. 6. That which I have here to do, is to inquire, whether, if it be the readiest way to acknowledge to begin with general maxims and build upon them, it be yet a safe way to take the principles which are laid down in any other science as unquestionable truths, and so receive them without examination, and adhere to them, without suffering them to be doubted of, because mathematicians have been so happy, or so fair, to use none but self-evident and undeniable. If this be so, I know not what may not pass for truth in morality, what may not be introduced and proved in natural philosophy. 7. Let that principle of some of the old philosophers, that all is matter, and that there is nothing else, be received for certain and indubitable, and it will be easy to be seen by the writings of some that have revived it again in our days, what consequences it will lead to. 8. Let any one, with Palermo, take the world, or with the Stoics, the Aether, or the Sun, or with Anneximines, the Air, to be God, and what a divinity, religion, and worship must we needs have! Nothing can be so dangerous as principles thus taken up without questioning or examination, especially if they be such as concern morality which influence men's lives and give a bias to all their actions. 9. Who might not justly expect another kind of life in Aristipus, who placed happiness in bodily pleasure, and Antisthenes, who made virtue sufficient to felicity? 10. And he who, with Plato, shall place beatitude in the knowledge of God, will have his thoughts raised to other contemplations than those who look not beyond this spot of earth, and those perishing things which are to be had in it. 11. He that, with Archelaus, shall lay it down as a principle that right and wrong, honest and dishonest are defined only by laws and not by nature, will have other measures of moral rectitude and gravity than those who take it for granted that we are under obligations and dissident to all human constitutions. 5. To do so is no certain way to truth. If, therefore, those that pass for principles are not certain, which we must have some way to know, that we may be able to distinguish them from those that are doubtful, but are only made so to us by our blind assent, we are liable to be misled by them, and instead of being guided into truth, we shall, by principles, be only confirmed in mistake and error. 6. But to compare clear, complete ideas under steady names. But since the knowledge of the certainty of principles, as well as of all other truths, depend only upon the perception we have of the agreement or disagreement of our ideas, the way to improve our knowledge is not, I am sure, blindly and with an implicit faith to receive and swallow principles, but is, I think, to get and fix in our minds clear, distinct and complete ideas, as far as they are to be had, and annex to them proper and constant names, and thus, perhaps without any other principles, but barely considering those perfect ideas and by comparing them one with another, finding their agreement and disagreement, and their several relations and habitudes, we shall get more true and clear knowledge by the conduct of this one rule than by taking up principles and thereby putting our minds into the disposal of others. 7. The true method of advancing knowledge is by considering our abstract ideas. 8. We must therefore, if we will proceed as reason advises, adapt our methods of inquiry to the nature of the ideas we examine, and the truth we search after. 9. General and certain truths are only founded in the habitudes and relations of abstract ideas. A sagacious and methodical application of our thoughts for the finding out these relations is the only way to discover all that can be put with truth and certainty concerning them into general propositions. By what steps we are to proceed in these is to be learned in the schools of the mathematicians, who, from very plain and easy beginnings, by gentle degrees and a continued chain of reasonings, proceed to the discovery and demonstration of truths that appear at first sight beyond human capacity. The art of finding proofs, and the admirable methods they have invented for the singling out and laying in order those intermediate ideas that demonstratively show the equality or inequality of unapplicable quantities, is that which has carried them so far, and produced such wonderful and unexpected discoveries. But whether something like this, in respect of other ideas, as well as those of magnitude, may not in time be found out, I will not determine. This, I think, I may say, that if other ideas that are the real as well as nominal essences of their species were pursued in the way familiar to mathematicians, they would carry our thoughts further, and with greater evidence and clearness than possibly we are apt to imagine. 8. By which morality also may be made clearer. This gave me the confidence to advance that conjecture which I suggest. Chapter 3. This, that morality is capable of demonstration as well as mathematics. For the ideas that ethics are conversant about, being all real essences, and such as I imagine have a discoverable connection and agreement one with another, so far as we can find their habitudes and relations, so far we shall be possessed of certain real and general truths. And I doubt not, but if a right method were taken, a greater part of morality might be made out with that clearness that could leave to a considering man no more reason to doubt than he could have to doubt of the truth of propositions in mathematics which have been demonstrated to him. 9. Our knowledge of substances is to be improved, not by contemplation of abstract ideas, but only by experience. In our search after the knowledge of substances, our want of ideas that are suitable to such a way of proceeding obliges us to a quite different method. We advance not here, as in the other, where our abstract ideas are real as well as nominal essences, by contemplating our ideas and considering their relations and correspondences, that helps us very little for the reasons that in another place we have at large set down. By which I think it is evident that substances afford matter of very little general knowledge, and the bare contemplation of their abstract ideas will carry us but a very little way in the search of truth and certainty. What then are we to do for the improvement of our knowledge in substantial beings? Here we are to take a quite contrary course. The want of ideas of their real essences sends us from our own thoughts to the things themselves as they exist. Experience here must teach me what reason cannot, and it is by trying alone that I can certainly know what other qualities coexist with those of my complex idea. VG, whether that yellow heavy fusible body I call gold be malleable or no, which experience, which way ever it prove in that particular body I examine, makes me not certain that it is so in all or any other yellow heavy fusible bodies, but that which I have tried. Because it is no consequence one way or the other from my complex idea, the necessity or inconsistence of malleability have no visible connection with the combination of that colour, weight and fusibility in any body. What I have said here of the nominal essence of gold, supposed to consist of a body of such a determinate colour, weight and fusibility, will hold true if malleableness, fixedness and solubility in aqua regia be added to it. Our reasonings from these ideas will carry us but a little way in the certain discovery of the other properties in those masses of matter wherein all these are to be found. Because the other properties of such bodies, depending not on these, but on that unknown real essence of which these also depend, we cannot by them discover the rest. We can go no further than the simple ideas of our nominal essence will carry us, which is very little beyond themselves, and so afford us but very sparingly any certain universal and useful truths. For upon trial, having found that particular piece, and all others of that colour, weight and fusibility that I ever tried, malleable, that also makes now, perhaps, a part of my complex idea, part of my nominal essence of gold, whereby, though I make my complex idea to which I affect the name gold to consist of more simple ideas than before, yet still, it's not containing the real essence of any species of bodies, it helps me not certainly to know, I say to know, perhaps it may be to conjecture, the other remaining properties of that body, further than they have a visible connection with some or all of the simple ideas that make up my nominal essence. For example, I cannot be certain from this complex idea whether gold be fixed or no, because as before, there is no necessary connection or inconsistence to be discovered betwixt a complex idea of a body yellow, heavy, fusible, malleable, betwixt these I say, and fixedness, so that I may certainly know that in whatsoever body these are found, their fixedness is sure to be. Here, again, for assurance, I must apply myself to experience as far as that reaches. I may have certain knowledge, but no further. Ten. Experience may procure is convenience. Not Science. I deny not, but a man accustomed to rational and regular experiments shall be able to see further into the nature of bodies and guess righter at their yet unknown properties than one that is a stranger to them. But yet, as I have said, this is but judgment and opinion, not knowledge and certainty. This way of getting and improving our knowledge in substances only by experience and history, which is all that the weakness of our faculties in this state of mediocrity which we are in this world can attain to, makes me suspect that natural philosophy is not capable is being made a science. We are able, I imagine, to reach very little general knowledge concerning the species of bodies and their several properties. Experiments and historical observations we may have, from which we may draw advantages of ease and health, and thereby increase our stock of conveniences for this life, but beyond this I fear our talents will reach not, nor are our faculties, as I guess, able to advance. Eleven. We are fitted for moral science, but only for probable interpretations of external nature. From whence it is obvious to conclude that since our faculties are not fitted to penetrate into the internal fabric and real essence of bodies, but yet plainly discover to us the being of a God and the knowledge of ourselves, enough to lead us into a full and clear discovery of our duty and great concernment. It will become us as rational creatures to employ those faculties we have about what they are most adapted to and follow the direction of nature where it seems to point us out the way. For it is rational to conclude that our proper employment lies in those inquiries and in that sort of knowledge which is most suited to our natural capacities and carries in it our greatest interest, i.e. the condition of our eternal estate. Hence I think I may conclude that morality is the proper science and business of mankind in general, who are both concerned and fitted to search out their summum bonum, as several arts, conversant about several parts of nature, are the lot and private talent of particular men, for the common use of human life and their own particular subsistence in this world. Of what consequence the discovery of one natural body and its properties may be to human life, the whole great continent of America is a convincing instance, whose ignorance in useful arts and want of the greatest part of the conveniences of life in a country that abounded with all sorts of natural plenty, I think may be attributed to their ignorance of what was to be found in a very ordinary, despicable stone. I mean the mineral of iron. And whatever we think of our parts or improvements in this part of the world, where knowledge and plenty seem to vie with each other, yet to any one that will seriously reflect upon it, I suppose it will appear past doubt that, where the use of iron lost among us, we should in a few ages be unavoidably reduced to the wants and ignorance of the ancient savage Americans, whose natural endowments and provisions come no way short of those of the most flourishing and polite nations. So that he who first made known the use of that contemptible mineral may be truly styled the father of arts and the author of plenty. 12. In the study of nature we must beware of hypothesis and wrong principles. I would not therefore be thought to disesteem or dissuade the study of nature. I readily agree the contemplation of his works gives us occasion to admire, revere and glorify their author, and, if rightly directed, may be of greater benefit to mankind than the monuments of exemplary charity that have, at so great charge, been raised by the founders of hospitals and alms houses. 13. He that first invented printing, discovered the use of the compass, or made public the virtue and the right use of kin-kina, did more for the propagation of knowledge, for the supply and increase of useful commodities, and saved more from the grave than those who built colleges, workhouses and hospitals. All that I would say is that we should not be too forwardly possessed with the opinion or expectation of knowledge where it is not to be had, or by ways that will not attain to it, that we should not take doubtful systems for complete sciences nor unintelligible notions for scientific demonstrations. In the knowledge of bodies we must be content to glean what we can from particular experiments, since we cannot, from a discovery of their real essences, grasp at a time whole sheaves and in bundles comprehend the nature and properties of whole species together. Where our inquiry is concerning coexistence, or repugnancy to coexist, which by contemplation of our ideas we cannot discover, their experience, observation and natural history must give us, by our senses and by retail, an insight into corporeal substances. The knowledge of bodies we must get by our senses, rarely employed in taking notice of their qualities and operations on one another, and what we hope to know of separate spirits in this world we must, I think, expect only from revelation. He that shall consider how little general maxims, precarious principles and hypotheses laid down at pleasure have promoted true knowledge, or helped to satisfy the inquiries of rational men after real improvements. How little, I say, the setting out at that end has, for many ages together, advanced men's progress towards the knowledge of natural philosophy. We'll think we have reason to thank those who in this latter age have taken another course and have trod out to us, though not an easier way to learn at ignorance, yet a sureer way to profitable knowledge. 13. The True Use of Hypothesis Not that we may not, to explain any phenomena of nature, make use of any probable hypothesis whatsoever. Hypothesis, if they are well made, are at least great helps to the memory and often direct us to new discoveries. But my meaning is that we should not take up any one too hastily, which the mind that would always penetrate into the causes of things and have principles to rest on is very apt to do, till we have very well examined particulars and made several experiments in that thing which we would explain by her hypothesis and see whether it will agree to them all, whether our principles will carry us quite through and not be as inconsistent with one phenomenon of nature that may seem to accommodate and explain another, and at least that we take care that the name of principles deceive us not, nor impose on us by making us receive that for an unquestionable truth which is really at best but a very doubtful conjecture, such as our most, I had almost said all, of the hypothesis in natural philosophy. 14. Clear and distinct ideas with settled names The finding of those intermediate ideas which show their agreement or disagreement are the ways to enlarge our knowledge, but whether natural philosophy be capable of certainty or no, the ways to enlarge our knowledge, as far as we are capable, seems to me in short to be these two. First. The first is to get and settle in our minds, determined ideas of those things whereof we have general or specific names, at least so many of them as we would consider and improve our knowledge in, or reason about. And if they be specific ideas of substances, we should endeavour also to make them as complete as we can, whereby I mean that we should put together as many simple ideas as being constantly observed to co-exist may perfectly determine the species, and each of those simple ideas which are the ingredients of our complex ones should be clear and distinct in our minds. For it being evident that our knowledge cannot exceed our ideas, as far as they are either imperfect, confused or obscure, we cannot expect to have certain perfect or clear knowledge. Secondly, the other is the art of finding out those intermediate ideas which may show us the agreement or repugnancy of other ideas which cannot be immediately compared. Fifteen. Mathematics and instance of this. That these two, and not the relying on maxims and drawing consequences from some general propositions, are the right methods of improving our knowledge in the ideas of other modes besides those of quantity. The consideration of mathematical knowledge will easily inform us. Where first we shall find that he has not a perfect and clear idea of those angles or figures of which he desires to know anything is utterly thereby incapable of any knowledge about them. Suppose but a man not to have a perfect exact idea of a right angle, a scalenum or trapezium, and there is nothing more certain than that he will in vain seek any demonstration about them. Further, it is evident that it was not the influence of those maxims which are taken for principles in mathematics that have led the masters of that science into those wonderful discoveries they have made. Let a man of good parts know all the maxims generally made use of in mathematics ever so perfectly and contemplate their extent and consequences as much as he pleases. He will, by their assistance, I suppose, scarce ever come to know that the square of the hypotenuse in a right-angled triangle is equal to the squares of the other two sides. The knowledge that the whole is equal to all its parts, and if you take equals from equals the remainder will be equal, etc., helped him not, I presume, to this demonstration and a man may, I think, pour long enough on those axioms without ever seeing one jot the more of mathematical truths. They have been discovered by the thoughts otherwise applied. The mind had other objects, other views before it, far different from those maxims, when it first got the knowledge of such truths in mathematics, which men, well enough acquainted with those received axioms, but ignorant of their method who first made these demonstrations, can never sufficiently admire. And who knows what methods to enlarge our knowledge in other parts of science may hereafter be invented, answering that of algebra in mathematics, which so readily finds out the ideas of quantities to measure others by, whose equality or proportion we could otherwise very hardly or perhaps never come to know. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. 1. Our knowledge partly necessary partly voluntary Our knowledge, as in other things, so in this, has so great a conformity with our sight that it is neither wholly necessary nor wholly voluntary. If our knowledge were altogether necessary, all men's knowledge would not only be alike, but every man would know all that is knowable. And if it were wholly voluntary, some men's little regard or value it, that they would have extreme little or not at all. Men that have senses cannot choose but receive some ideas by them. And if they have memory, they cannot but retain some of them. And if they have any distinguishing faculty, cannot but perceive the agreement or disagreement of some of them, one with another. I see that as eyes, if you will open them by day, cannot but see some objects and perceive a difference in them. But though men with his eyes open in delight cannot but see, yet there be certain objects which he may choose whether he will turn his eyes to. There may be in his reach a book containing pictures and discourses capable to delight or instruct him, which yet he may never have the will to open, never take the pains to look into. Two, the application of our faculty's voluntary, but they being employed, we know as things are, not as we please. There is also another thing in a man's power, and that is, though he turns his eyes sometimes towards an object, yet he may choose whether he will curiously survey it and with an intent application and ever to observe accurately all that is visible in it. But yet, what he does see, he cannot see otherwise than he does. It depends not on his will to see that black which appears yellow, nor to persuade himself that what actually scolds him feels cold. The earth will not appear painted with flowers, nor do feels covered with verger whenever he has a mind to it. In the cold winter, he cannot help seeing it white and hoary if he will look abroad. Just this is it with our understanding. All that is voluntary in our knowledge is the employing or withholding any of our faculties from this or that sort of objects, and a more or less accurate survey of them. But they being employed, our will have a no power to determine the knowledge of the mind one way or another. That is done only by the objects themselves as far as they are clearly discovered. And therefore, as far as men senses are conversant about external objects, the mind cannot but receive those ideas which are presented by them and be informed of the existence of things without. And so far as men's thoughts converse with their own determined ideas, they cannot but in some measure observe the agreement or disagreement that is to be found among some of them, which is so far knowledge. And if they have names for those ideas which they have best considered, they must need to be assured of the truth of those propositions which express that agreement or disagreement they perceive in them and be undoubtedly convinced of those truths. For what a man sees, he cannot but see. And what he perceives, he cannot but know that he perceives. 3. Instance in numbers. Thus, he that has got the ideas of numbers and has taken the pains to compare 1, 2 and 3 to 6 cannot choose but know that they are equal. He that has got the idea of a triangle and found the ways to measure its angles in their magnitudes is certain that its three angles are equal to two right ones and can as little doubt of that as of this truth that it is impossible for the same thing to be and not to be. 4. Instance in natural religion. He also that has the idea of an intelligent but frail and weak being made by and depending on another who is eternal, omnipotent, perfectly wise and good will certainly know that man is to honour, fear and obey God as that the sun shines when he sees it. For if he has but the ideas of two such beings in his mind and will turn his thoughts that way and consider them he will certainly find that the inferior, finite and dependent is under an obligation to obey the supreme and infinite as he is certain to find that 3, 4 and 7 are less than 15 if he will consider and compute those numbers nor can he be sure in a clear morning when the sun is risen if he will but open his eyes and turn them that way but yet these truths being ever so certain, ever so clear he may be ignorant of either or all of them who will never take the pains to employ his faculties as he should to inform himself about them. End of Section 14 Section 15 of an essay concerning human understanding by John Locke, Book 4 of Knowledge and Probability This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org Chapter 14 of Judgment 1. Our knowledge being short, we want something else. The understanding faculties being given to man not barely for speculation but also for the conduct of his life man would be at a great loss if he had nothing to direct him but what has the certainty of true knowledge. For that being very short and scanty as we have seen it would be often utterly in the dark and most of the actions of his life perfectly at his stand had he nothing to guide him in the absence of clear and certain knowledge. He that will not eat till he has demonstration that it will nourish him he that will not stir till infallibly knows the business he goes about while succeed will have little else to do but to sit still and perish. 2. What used to be made of this twilight state? Therefore has God has set some things in bright daylight as he has given us some certain knowledge though limited to a few things in comparison probably as a taste of what intellectual creatures are capable of to excite in us a desire and endeavor after a better state. So in the greatest part of our concernments he has afforded us only the twilight as I may so say of probability suitable I presume to that state of mediocrity and probation a ship he has been pleased to place us in here wherein to check our overconfidence and presumption we might by everyday's experience be made sensible of our short-sightedness and liable-ness to error. The sense we're of might be a constant admonition to us to spend the days of this our pilgrimage with industry and care in the search and following of that way which might lead us to a state of greater perfection. It being highly rational to think even were revelations silent in the case that as men employ those talents God has given them here they shall accordingly receive their rewards at the close of the day when their son shall set and night shall put an end to their labours. 3. Judgment or ascent probability supplies our want of knowledge The faculty which God has given men to supply the want of clear and certain knowledge in cases where that cannot be had is judgment whereby the man takes its ideas to agree or disagree or which is the same any proposition to be true or false without perceiving a demonstrative evidence in the proofs. The mind sometimes exercises this judgment out of necessity where demonstrative proofs and certain knowledge are not to be had and sometimes out of laziness and skillfulness or haste even where demonstrative and certain proofs are to be had. Men often stay not worryily to examine the agreement or disagreement of two ideas which they are desirous or concerned to know but either incapable of such attention as is requisite in a long train of gradations or impatient of delay, lightly cast their eyes on or wholly passed by the proofs and so without making out the demonstration determine of the agreement or disagreement of two ideas as it were by view of them as they are at a distance and take it to be the one or the other as seems most likely to them upon such a loose survey. This faculty of the mind when it is exercised immediately about things is called judgment. When about proofs delivered in words is most commonly called ascent or descent which being the most usual way where in the mind has occasion to employ this faculty I shall under these terms treat of it as least liable in our language to equivocation. 4. Judgment is a presuming things to be so without perceiving it. Thus the minus two faculties conversant about truth and falsehood. First knowledge whereby it certainly perceives and is undoubtedly satisfied of the agreement or disagreement of any ideas. Secondly judgment which is the putting ideas together or separating them from one another in the mind when there are certain agreement or disagreement is not perceived but presumed to be so which is as the word imports taken to be so before it certainly appears and if it so unites or separates them as in reality things are it is right judgment. End of section 15 Section 16 of an essay concerning human understanding by John Locke Book 4 of knowledge and probability This is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org Recording by Jennifer Henry Chapter 15 of probability 1. Probability is the appearance of agreement upon fallible proofs as demonstration is the showing the agreement or disagreement of two ideas by the intervention of one or more proofs which have a constant immutable and visible connection one with another so probability is nothing but the appearance of such an agreement or disagreement by the intervention of proofs whose connection is not constant and immutable or at least is not perceived to be so but is or appears for the most part to be so and is enough to induce the mind to judge the proposition to be true or false rather than the contrary for example in the demonstration of it a man perceives the certain immutable connection there is of equality between the three angles of a triangle and those intermediate ones which are made use of to show their equality to two right ones and so by an intuitive knowledge of the agreement or disagreement of the intermediate ideas in each step of the progress the whole series is continued with an evidence which clearly shows the agreement or disagreement of those three angles inequality to two right ones and thus he has certain knowledge that it is so but another man who never took the pains to observe the demonstration hearing a mathematician a man of credit affirm the three angles of a triangle to be equal to two right ones a sense to it i.e. receives it for true in which case the foundation of his ascent is the probability of the thing the proof being such as for the most part carries truth with it the man on whose testimony he receives it not being want to affirm anything contrary to or besides his knowledge especially in matters of this kind so that that which causes his ascent to this proposition that the three angles of a triangle are equal to two right ones that which makes him take these ideas to agree without knowing them to do so is the wanted veracity of the speaker in other cases or his supposed veracity in this to it is to supply our want of knowledge our knowledge as has been shown being very narrow and we not happy enough to find certain truth in everything which we have occasion to consider most of the propositions we think reason this course may act upon are such as we cannot have undoubted knowledge of their truth yet some of them borders so near upon certainty that we make no act according to the ascent as resolutely as if they were infallibly demonstrated and that our knowledge of them was perfect and certain but there being degrees herein from the very neighborhood of certainty and demonstration quite down to improbability and unlikeness even to the confines of impossibility and also degrees of ascent from full assurance and confidence quite down to conjecture doubt and distrust I shall come now having as I think found out the bounds of human knowledge and certainty in the next place to consider the several degrees and grounds of probability and ascent or faith three being that which makes us presume things to be true before we know them to be so probability is likeliness to be true the very notation of the word signifying such a proposition for which there be arguments or proofs to make it pass or be received for true the entertainment the mind gives this sort of proposition is called belief, ascent or opinion which is the admitting or receiving any proposition for true upon arguments or proofs that are found to persuade us to receive it as true without certain knowledge that it is so and herein lies the difference between probability and certainty faith and knowledge that in all the parts of knowledge there is intuition each immediate idea each step has its visible and certain connection in belief not so that which makes me believe is something extraneous to the thing I believe something not evidently joined on both sides to and so not manifestly showing the agreement or disagreement of those ideas that are under consideration four the grounds of probability are two conformity with our own experience or the testimony of others probability then being to supply the defect of our knowledge and to guide us where that fails is always conversant about propositions whereof we have no certainty but only some inducements to receive them for true the grounds of it are in short these two following first the conformity of anything with our own knowledge, observation and experience secondly the testimony of others vouching their observation and experience in the testimony of others is to be considered one the number two the integrity three the skill of the witnesses four the design of the author where it is a testimony out of a book cited five the consistency of the parts and circumstances of the relation six contrary testimonies five in this all the arguments pro and con ought to be examined before we come to a judgment probability wanting that intuitive evidence which infallibly determines the understanding and produces certain knowledge the mind if it will proceed rationally ought to examine all the grounds of probability and see how they make more or less for or against any proposition before it ascends to or descents from it and upon a do balancing the whole reject or receive it with a more or less firm ascent proportionably to the preponderancy of the greater grounds of probability on one side or the other for example if I myself see a man walk on the ice it is past probability it is knowledge but if another tells me he saw a man in England in the midst of a sharp winter walk upon water hardened with cold this has so great conformity with what is usually observed to happen that I am disposed by the nature of the thing itself to ascent to it unless some manifest suspicion attend the relation of that matter of fact but if the same thing be told to one born between the tropics who never saw nor heard of any such thing before there the whole probability relies on testimony and as the relators are more in number and of more credit and have no interest to speak contrary to the truth so that matter of fact is like to find more or less belief though to a man whose experience has always been quite contrary and who has never heard of anything like it the most untainted credit of a witness will scarce be able to find belief as it happened to a Dutch ambassador who entertaining the king of Siam with the particularities of Holland which he was inquisitive after amongst other things told him that the water in his country would sometimes in cold weather be so hard that men walked upon it and that it would bear an elephant if he were there to which the king replied hitherto I have believed the strange things you have told me because I look upon you as a sober, fair man but now I am sure you lie probable arguments capable of great variety upon these grounds depends the probability of any proposition and as the conformity of our knowledge as the certainty of observations as the frequency and constancy of experience and the number and credibility of testimonies do more or less agree or disagree with it so is any proposition in itself more or less probable there is another I confess which though by itself it be no true ground of probability yet is often made use of for one by which men most commonly regulate their assent and upon which they pin their faith more than anything else and that is the opinion of others though there cannot be a more dangerous thing to rely on nor more likely to mislead one since there is much more falsehood and error among men than truth and knowledge and if the opinions and persuasions of others whom we know and think well of be a ground of assent men have reason to be heathens in Japan Mahatmatans in Turkey Papists in Spain Protestants in England and the Lutherans in Sweden but of this wrong ground of assent I shall have occasion to speak more at large in another place end of section 16 recording by Jennifer Henry section 17 of an essay concerning human understanding by John Locke book 4 of knowledge and probability this is a LibriVox recording all LibriVox recordings are in the public domain for more information or to volunteer please visit LibriVox.org recording by Jennifer Henry chapter 16 of the degrees of assent one our assent ought to be regulated by the grounds of probability the grounds of probability we have laid down in the foregoing chapter as they are the foundations on which our assent is built so are they also the measure whereby it's several degrees are or ought to be regulated only we are to take notice that whatever grounds of probability there may be they yet no further on the mind which searches after truth and endeavors to judge right then they appear at least in the first judgment or search that the mind makes I confess in the opinions men have and firmly stick to in the world their assent is not always from an actual view of the reasons that at first prevailed with them it being in many cases almost impossible and in most very hard even for those who have very admirable memories to retain all the proofs which upon a due examination made them embrace that side of the question it suffices that they have once with care and fairness sifted the matter as far as they could and that they have searched into all the particulars that they could imagine to give any light to the question with the best of their skill cast up the account upon the whole evidence and thus having once found on which side the probability appeared to them after as full and exact an inquiry as they can make they lay up the conclusion in their memories as a truth they have discovered and for the future they remain satisfied with the testimony of their memories that this is the opinion that by the proofs they have once seen of it deserves such a degree of their assent as they afford it 2 these cannot always be actually in view and then we must content ourselves with the remembrance that we once saw ground for such a degree of assent this is all that the greatest part of men are capable of doing in regulating their opinions and judgements unless a man will exact of them either to retain distinctly in their memories all the proofs concerning any probable truth and that too in the same order and regular deduction of consequences in which they have formally placed or seen them which sometimes is enough to fill a large volume on one single question or else they must require a man for every opinion that he embraces every day to examine the proofs both which are impossible it is unavoidable therefore that the memory be relied on in the case and that men be persuaded of several opinions whereof the proofs are not actually in their thoughts nay, which perhaps they are not able actually to recall without this the greatest part of men must be either very skeptics or change every moment and yield themselves up to whoever having lately studied the question offers them arguments which for want of memory they are not able to presently answer three, the ill consequence of this if our former judgments were not rightly made I cannot but own that men's speaking to their past judgment and adhering firmly to conclusions formerly made is often the cause of great obstinacy in error and mistake but the fault is not that they rely on their memories for what they have before well judged but because they judged before they had well examined may we not find a great number not to say the greatest part of men that think they have formed right judgments of several matters and that for no other reason but because they never thought otherwise that themselves to have judged right only because they never questioned never examined their own opinions which is indeed to think they judged right because they never judged at all and yet these of all men hold their opinions with the greatest stiffness those being generally the most fierce and firm in their tenants who have least examined them what we once know we are certain is so and we may be secure that there are no latent proofs undiscovered which may overturn our knowledge or bring it in doubt but in matters of probability it is not in every case we can be sure that we have all the particulars before us that anyway concern the question and that there is no evidence behind and yet unseen which may cast the probability on the other side and outweigh all that at present seems to preponderate with us who almost is there that hath the leisure patience and means to collect together all the proofs concerning most of the opinions he has so as safely to conclude that he hath a clear and full view and that there is no more to be alleged for his better information and yet we are forced to determine ourselves on the one side or other the conduct of our lives and the management of our great concerns will not bear delay for those depend for the most part on the determination of our judgment in points wherein we are not capable of certain and demonstrative knowledge and wherein it is necessary for us to embrace the one side or the other for the right use of it mutual charity and forbearance in a necessary diversity of opinions since therefore it is unavoidable to the greatest part of men if not all to have several opinions without certain and indubitable proofs of their truth and it carries too great an imputation of ignorance, lightness or folly for men to quit and renounce their former tenants presently upon the offer of an argument which they cannot immediately answer and show the insufficiency of it would, me thinks become all men to maintain peace and the common offices of humanity and friendship in the diversity of opinions since we cannot reasonably expect that anyone should readily and obsequiously quit his own opinion and embrace ours with a blind resignation of an authority which the understanding of man acknowledges not for however it may often mistake it can own no other guide but reason nor blindly submit to the will and dictates of another if he you would bring over to your sentiments be one that examines before he ascents you must give him leave at his leisure to go over the account again and recalling what is out of his mind examine all the particulars to see on which side the advantage lies and if he will not think our arguments of weight enough to engage him anew in so much pains it is but what we often do ourselves in the like case and we should take it amiss if others should prescribe to us what points we should study be one who takes his opinions upon trust how can we imagine that he should renounce those tenants which time and custom have so settled in his mind that he thinks them self-evident and of an unquestionably certainty or which he takes to be impressions he has received from God himself or from men sent by him how can we expect I say that opinions thus settled given up to the arguments or authority of a stranger or adversary especially if there be any suspicion of interest or design as there never fails to be where men find themselves ill trusted we should do well to commiserate our mutual ignorance and endeavour to remove it in all the gentle and fair ways of information and not instantly treat others ill as obstinate and perverse because they will not renounce their own and receive our opinions or at least those we would force upon them when it is more than probable that we are no less obstinate in not embracing some of theirs for where is the man that has incontestable evidence of the truth of all that he holds or of the falsehood of all he condemns or can say that he has examined to the bottom all his own or other men's opinions the necessity of believing without knowledge may often upon very slight grounds in this fleeting state of action and blindness we are in should make us more busy and careful to inform ourselves then constrain others at least those who have not thoroughly examined to the bottom all tendons must confess they are unfit to prescribe to others and are unreasonable in imposing that as truth on other men's belief which they themselves have not searched into nor weighed the arguments of probability on which they should receive or reject it those who have fairly and truly examined and are thereby got past doubt in all the doctrines they profess and govern themselves by would have adjuster pretence to require others to follow them but these are so few in number and find so little reason to be magisterial in their opinions that nothing insolent and imperious is to be expected from them and there is reason to think that if men were better instructed themselves they would be less imposing on others five probability is either of sensible matter of fact capable of human testimony or of what is beyond the evidence of our senses but to return to the grounds of assent and the several degrees of it we are to take notice that the propositions we receive upon inducements of probability are of two sorts either concerning some particular existence or as it is usually termed matter of fact which falling under observation is capable of human testimony or else concerning things which being beyond the discovery of our senses are not capable of any such testimony six concerning the first of these these particular matter of fact one the concurrent experience of all other men with ours produces assurance approaching to knowledge where any particular thing consonant to the constant observation of ourselves and others in the like case comes attested by the concurrent reports of all that mention it we receive it as easily and build as firmly upon it as if it were certain knowledge and we reason and act there upon with as little doubt as if it were perfect demonstration thus if all Englishman who have occasion to mention it should affirm that it froze in England the last winter or that there were swallows seen there in the summer I think a man could almost as little doubt of it as that seven and four eleven the first therefore and highest degree of probability is when the general consent of all men in all ages as far as it can be known concurs with a man's constant and never failing experience in like cases to confirm the truth of any particular matter of fact attested by fair witnesses such are all the stated constitutions and properties of bodies and the regular proceedings of causes and effects in the ordinary course of nature this we call an argument from the nature of things themselves for what our own and other men's constant observation has found always to be after the same manner that we with reason conclude to be the effect of steady and regular causes though they come not within the reach of our knowledge thus that fire warmed a man made lead fluid and changed the color or consistency in wood or charcoal that iron sunk in water and swam in quicksilver these and the like propositions about particular facts being agreeable to our constant experience as often as we have to do with these matters and being generally spoke of when mentioned by others as things found constantly to be so and therefore not so much as controverted by anybody we are put past doubt that a relation affirming any such thing to have been or any predication that it will happen again in the same manner is very true these probabilities rise so near to certainty that they govern our thoughts as absolutely and influence all our actions as fully as the most evident demonstration and in what concerns us we make little or no difference between them and certain knowledge our belief thus grounded rises to tolerance 7 2 unquestionable testimony and our own experience that a thing is for the most part so produce confidence the next degree of probability is when I find by my own experience and the agreement of all others that mention it a thing to be for the most part so and that the particular instance of it is attested by many and undoubted witnesses V.G. history giving us such an account of men in all ages and my own experience as far as I had an opportunity to observe confirming it that most men prefer their private advantage to the public if all historians that write of Tiberius say that Tiberius did so it is extremely probable and in this case our ascent has a sufficient foundation to raise itself to a degree which we may call confidence 8 3 fair testimony and the nature of the thing indifferent produce unavoidable ascent in things that happen indifferently as that a bird should fly this or that way that it should enter on a man's right or left hand etc when any particular matter of fact is vouched by the concurrent testimony of unsuspected witnesses there our ascent is also unavoidable thus that there is such a city in Italy as Rome that about 1700 years ago there lived in it a man called Julius Caesar general and that he won a battle against another called Pompeii this though in the nature of the thing there be nothing for nor against it yet being related by historians of credit and contradicted by no one writer a man cannot avoid believing it and can as little doubt of it as he does of the being and actions of his own acquaintance whereof he himself is a witness 9 experience and testimonies clashing infinitely vary the degrees of probability thus far the matter goes easy enough probability upon such grounds carries so much evidence with it that it naturally determines the judgment and leaves us as little liberty to believe or disbelieve as a demonstration does whether we will know or be ignorant the difficulty is when testimonies contradict common experience and the reports of history and witnesses clash with the ordinary course of nature or with one another there it is where diligence, attention and exactness are required to form a right judgment and to proportion the assent to the different evidence and probability of the thing which rises and falls according as those two foundations of credibility these common observation in like cases and particular testimonies in that particular instance favor or contradict it these are liable to so great variety of contrary observations circumstances, reports different qualifications tempers, designs oversights etc of the reporters that it is impossible to reduce to precise rules the various degrees wherein men give their assent this only may be said in general that as the arguments and proofs pro and con upon due examination nicely weighing every particular circumstance shall to anyone appear upon the whole matter in a greater or less degree to preponderate on either side so they are fitted to produce in the mind such different entertainments as we call belief conjecture guess doubt, wavering distrust belief etc ten traditional testimonies the further removed the less their proof becomes this is what concerns assent in matters wherein testimony is made use of concerning which I think it may not be a miss to take notice of a rule observed in the law of England which is that though the attested copy the record be good proof yet the copy of a copy ever so well attested and by ever so credible witnesses will not be admitted as a proof in judicature this is so generally approved as reasonable and suited to the wisdom and caution to be used in our inquiry after material truths that I never yet heard of anyone that blamed it this practice if it be allowable in the decisions of right and wrong carries this observation along with it these that any testimony the further off it is from the original truth the less force and proof it has the being and existence of the thing itself is what I call the original truth a credible man vouching his knowledge of it is a good proof but if another equally credible do witness it from his report the testimony is weaker and a third that attests the hearsay of and hearsay is yet less considerable so that in traditional truths each remove weakens the force of the proof and the more hands the tradition has successively passed through the less strength and evidence does it receive from them this I thought necessary to be taken notice of because I find amongst some men the quite contrary commonly practiced who look on opinions to gain force by growing older and what a thousand years since would not to a rational man contemporary with the first voucher have appeared at all is now urged as certain beyond all question only because several have since from him said it one after another upon this ground propositions evidently faults or doubtful enough in their first beginning come by an inverted rule of probability to pass for authentic truths and those which found reserved little credit from the mouths of their first authors are thought to grow venerable by age are urged as undeniable 11 yet history is of great use I would not be thought here to lessen the credit and use of history it is all the light we have in many cases and we receive from a great part of the useful truths we have with a convincing evidence I think nothing more valuable than the records of antiquity I wish we had more of them and more uncorrupted but this truth itself forces me to say that no probability can rise higher than its first original what has no other evidence than the single testimony of one only witness must stand or fall by his only testimony whether good, bad, or indifferent and those cited afterwards by hundreds of others one after another is so far from receiving any strength thereby that it is only the weaker passion, interest inadvertency mistake of his meaning a thousand odd reasons or capricious men's minds are acted by impossible to be discovered may make one man quote another man's words or meaning wrong he that has but ever so little examined the citations of writers cannot doubt how little credit the quotations deserve where the originals are wanting unconsequently how much less quotations of quotations can be relied on this is certain that what in one age was affirmed upon slight grounds can never after come to be more valid in future ages by being often repeated but the further still it is from the original the less valid it is and has always less force in the mouth or writing of him that last made use of it than in his from whom 12 secondly in things which sense cannot discover analogy is the great rule of probability secondly the probabilities we have hitherto mentioned are only such as concern matter of fact and such things as are capable of observation and testimony there remains that other sort concerning which can entertain opinions with variety of ascent though the things be such that falling not under the reach of our senses they are not capable of testimony such are one the existence nature and operations of finite immaterial beings without us as spirits angels devils etc or the existence of material beings which either for their smallness in themselves or remoteness from us our senses cannot take notice of as whether there be any plants animals and intelligent inhabitants in the planets and other mansions of the vast universe two concerning the manner of operation in most parts of the works of nature where in though we see the sensible effects yet their causes are unknown and we perceive not the ways and manner how they are produced we see animals are generated nourished and move the lodestone draws iron and the parts of a candle successively melting turn into flame and give us both light and heat these and the like effects we see and know but the causes that operate and the manner they are produced in we can only guess and probably conjecture for these and the like coming not within the scrutiny of human senses cannot be examined by them or be attested by anybody and therefore can appear more or less probable only as they more or less agree to truths that are established in our minds and as they hold proportion to other parts of our knowledge and observation analogy in these matters is the only help we have and it is from that alone we draw all our grounds of probability thus observing that the bare rubbing of two bodies violently one another produces heat and very often fire itself we have reason to think that what we call heat and fire consists in a violent agitation of the imperceptible minute parts of the burning matter observing likewise that the different refractions of pollucid bodies produce in our eyes the different appearances of several colors and also that the different ranging and layering the superficial parts of several bodies as of velvet watered silk etc does the like we think it probable that the color and shining of bodies is in them nothing but the different arrangement and refraction of their minute and insensible parts thus finding in all parts of the creation that fall under human observation that there is a gradual connection of one with another without any great discernible gaps between in all that great variety of things we see in the world which are so closely linked together that in the several ranks of beings it is not easy to discover the bounds betwixt them we have to be persuaded that by such gentle steps things ascend upward in degrees of perfection it is a hard matter to say where sensible and rational begin and where insensible and irrational end and who is there quick-sighted enough to determine precisely which is the lowest species of living things and which the first of those which have no life things as far as we can observe lessen and augment as the quantity does in a regular cone where though there be a manifest odds betwixt the bigness of the diameter at a remote distance yet the difference between the upper and under where they touch one another is hardly discernible the difference is exceeding great between some men and some animals but if we will compare the understanding and abilities of some men and some brutes we shall find so little difference that it will be hard to say that that of man is either clearer or larger observing I say such gradual and gentle descents downward in those parts of the creation that are beneath man the rule of analogy may make it probable that it is so also in things above us and our observation and that there are several ranks of intelligent beings excelling us in several degrees of perfection ascending upwards towards the infinite perfection of the creator by gentle steps and differences that are every one at no great distance next to it this sort of probability which is the best conduct of rational experiments and the rise of hypothesis has also its use and influence and a wary reasoning from analogy leads us often into the discovery of truths and useful productions which would otherwise lie concealed one case the common experience lessens not the testimony though the common experience and the ordinary course of things have justly a mighty influence on the minds of men to make them give or refuse credit to anything proposed to their belief yet there is one case wherein the strangeness of the fact lessens not the ascent to a fair testimony of it for where such supernatural events are suitable to ends aimed at by him who has the power to change the course of nature there under such circumstances that may be the fitter to produce belief by how much the more they are beyond or contrary to ordinary observation this is the proper case of miracles which well attested do not only find credit themselves but give it also to other truths which need such confirmation 14 the bare testimony of divine revelation is the highest certainty besides those we have hitherto mentioned there is one sort of propositions that challenge the highest degree of consent upon bare testimony whether the thing proposed agree or disagree with common experience and the ordinary course of things or no the reason whereof is because the testimony is of such and one as cannot deceive nor be deceived and that is of God himself this carries with it an assurance beyond doubt evidence beyond exception this is called by a peculiar name revelation and our ascent to it faith which as absolutely determines our minds and as perfectly excludes all waverings as our knowledge itself and we may as well doubt of our own being as we can whether any revelation from God be true faith is a settled and sure principle of ascent and assurance and leaves no manner of room for doubt or hesitation only we must be sure that it be a divine revelation and that we understand it right else we shall expose ourselves to all the extravagancy of enthusiasm and all the error of wrong principles we have faith and assurance in what is not divine revelation and therefore in those cases our ascent can be rationally no higher than the evidence of it's being a revelation and that this is the meaning of the expression it is delivered in if the evidence of it's being a revelation or that this is it's true sense be only on probable proofs our ascent can reach no higher than an assurance or diffidence arising from the more or less apparent probability of the proofs but of faith and the precedency it ought to have before other arguments of persuasion I shall speak more hereafter where I treat it as it is ordinarily placed in contra distinction to reason though in truth it being nothing else but an ascent founded on the highest reason end of section 17 recording by Jennifer Henry