 This lecture would focus on the following topics. We will discuss the Cartesian philosophy Descartes. The method of philosophy because Descartes is so peculiar is one very important philosopher who introduces the concern for a method for philosophy like mathematics like sciences particularly as it is there in mathematics. Because mathematical method is a method which enables one to arrive at absolute certainty. Then the concept of doubt that is another very important aspect of Cartesian philosophy and then his conception of indubitable knowledge which is actually working as a guiding force in his entire philosophy. So, I have already discussed the passage to modern philosophy and Descartes is also known as the father of modern philosophy. Of course, this status of Descartes as a very important thinker is undoubted and unquestioned. But at the same time we should also understand that in the contemporary period there are no much takers for Descartes methodology approaches and his philosophical positions. But at the same time he is one of the very important philosophers in the history of Christian philosophy. Now, when we talk about modern philosophy as such before we really try to understand Cartesian contributions. Let us have a very brief introduction about the important concerns of modern philosophy and here we could see that suddenly there is a focus on epistemological questions. We could see that the Greek philosophers by and large were concerned more about ontology more about metaphysics. So, you have this philosophers the great system builders Plato and Aristotle. They were all philosophers who were concerned about metaphysical ontological issues. Of course, they also had their epistemology, but the central focus was on the questions of reality metaphysics. What is reality? Now, with modern philosophy the shift is to knowledge. So, the shift is to epistemology. We could see that by 20th century there is another shift it is to language linguistic philosophy. Now, philosophies objective in the modern period has to be understood very clearly. It is always concerned about knowledge, the source of knowledge, the kinds of knowledge, the purposes of knowledge, the limitations of knowledge. And it as I already mentioned no longer deals with the questions of ultimate reality. Philosophy deals with knowledge, the nature, kinds, limitations and sources of knowledge and with this very important phenomena a cultural phenomena which happens simultaneously with this is the rise of modern science as a cultural institution. The spread of the scientific temperament in Europe. So, this is also very peculiar because any philosophy is situated in a historical context. And modern philosophy is also to understand modern philosophy we should know the historical context, the important historical events that took place during that period. So, one of the very important factors is the rise of modern science as a cultural institution. And when we talk about this developments in science, there are several developments in sciences, various sciences this period has witnessed. What happened was the Catholic church is now no longer the only source of authority. So, gradually scientist have started understanding the world and they could able to do that with a greater levels of certainty and success. So, this is actually resulted in the Catholic church losing its control over culture. Again scientific rationality raises a strong claim of authority in culture and human life. So, science has this claim to understand the world. Scientists could better understand the world than anyone else. Then science exposed many dogmas that prevailed for centuries as unquestioned. Again everything needs to be questioned. So, this is another very important feature of scientific temperament. Nothing is accepted in its face value. Everything needs to be questioned and thoroughly interrogated before we accept it as valid or true. So, this scientific temperament had its impact on philosophy as well. Philosophers also rejected the value of what you call in the scholastic period it was revelation authority. So, science or scientific rationality has become the sole authority for all knowledge. Nothing can be affirmed as true without critical examination. So, faith has no role in culture or rather it has very little role in culture rather reason gains prominence. So, this are some of the peculiar features of modern philosophy associated with the developments in science took place during this period. Now, when we talk about science the emergence of modern science as is a very important event in human history and when we talk about science there are two important elements in scientific method. We have to discuss this because we are also going to can deal with the question of method. How the question of method has become important in philosophy? This is what we are going to see. So, there are two elements of scientific method the empirical element and the rational element. The empirical element deals with sense observation. There is the question what is there in front of us? So, several equipment sophisticated equipment could be developed in order to observe the world both the microscopes and the telescopes were discovered to understand the world in a better way. So, sense observation is so integral for scientific method to progress and this is the most obvious thing that what is there in front of us? Try to understand it by seeing it by observing it. It is a very obvious procedure in all knowledge acquisition which is nothing but a part of common sense. So, in that sense science would also claim to be an extension of our common sensical approaches, but of course it is a very significant extension. Common sense does not employ any method, but science employs a systematic method. So, it is a systematic extension of common sense we can see and again this is to also highlight the inductive element observation what is happening? Events one by one has to be observed. So, the inductive element is also affirmed. Now, when we come to the rational element it is based completely on reason human mind has that capacity to know things rationally and that aspect is highlighted. No one would be able to deny this and it supplements the common sense which we mentioned earlier. So, in one sense scientific method demands a kind of collaboration between these two elements the empirical element with the rational element or in one sense we can say that the inductive element as well as the deductive element the inductive approach and the deductive approach based on these two approaches there are two important schools of modern philosophy empiricism and rationalism and the two important schools and the division of these schools they distinguish each other because the question the division is based on the question of the source of knowledge what is the source of human knowledge that is the question empiricist would say that it is experience sense experience is a fundamental source of knowledge or every knowledge begins with sense experience. Later on we have reason plays a very important role that even empiricist would accept, but as far as the starting point of knowledge is concerned as far as the fundamental source of knowledge is concerned empiricist would claim that it is experience sense observation while on the other hand rationalism would claim that all knowledge depends on the innate structures of the mind. So, in one sense you can see a instance of Platonism here this lecture is dedicated to understand Descartes philosophy who is a prominent rationalist philosopher. Rationalism is the view that genuine knowledge consist of universal and necessary judgments the gall of thought is a system of truths in which the different propositions are logically related to one another. So, this aspect is emphasized by all rationalists genuine knowledge consist of universal and necessary judgments and they are interconnected logically interconnected propositions and this ultimately points to a conception of knowledge which is presented in mathematics. In mathematics what happens is that we begins with a set of axioms which are self evident we never question them these axioms are supposed to be self evident and everything else is deducted from these axioms. So, a similar or the same method is applied to the domain of knowledge epistemology by the rationalist and they claim that that is the ideal model of knowledge a mathematical conception. So, they would eventually affirm that the origin of knowledge needs to be searched not in sense perception, but it has its foundations in reason in human rationality as such. So, reason needs to be understood as a complex structure rational structure and this is located in the human mind that is the basic assumption. So, the conception of innate ideas is derived from this notion certain truths are natural or native innate to reason and are a priori. So, this emphasis on the a priori conception of knowledge there are certain truths which are natural to the mind natural to the reason they are native or innate to the mind is a fundamental assumption of rationalism where we can see the shades of Platonism. Again reason and intuition are treated as sources of genuine knowledge and not sensation and experience and it considers all or most ideas are innate rather than adventitious and then again the goal of inquiry is certain knowledge and not something which is merely probable. So, this is where the rationalist would criticize the empiricist in empiricism which emphasizes on sense perception what happens is that we completely rely on our sensations. So, I would say that there is a computer in front of me a black computer in front of me, but then again when I say a black computer this is not absolutely certain knowledge this depends on several factors the light in this room and various other limitations of my sensory perception all these are factors that probably play a very important role in sensations. So, they think that this cannot be considered as ultimate. So, certain knowledge or ultimately the goal of enquiries certain knowledge and not something which is merely probable and the three philosophers we would be discussing in these lecture series are Rene Descartes 1596 to 1650 then it is Spinoza 1632 to 1677 Leibniz 1646 to 1716 they are the most important philosophers there are many others, but we would be concentrating our lecture series would be concentrating on these three important thinkers. And when you talk about empiricism as I already mentioned the source of knowledge is sense perception and they deny the possibility of innate ideas there are no prepositions that yield necessary or absolute knowledge everything is based on sensation according to them. And the three important philosophers which we are going to consider in this lecture series are John Locke 1632 to 1704 George Berkeley 1685 to 1753 and David Hume 1711 to 1776. And these two schools rationalism and empiricism both of them accept reason as a faculty of the mind through which truths about reality or not. So, they both agree that reason is paramount this is acceptable to both the schools with regard to the question of the source of knowledge there is a disagreement and neither a firm that all knowledge comes from experience. So, one should not confuse that rationalism emphasizes only on reason and empiricism asserts only the value of sense experience no for empiricist also reason is very important even they do not say that all knowledge come from experience they say that it begins the source of knowledge there are some knowledge that does not derive from experience even the empiricist also accepted. So, during our discussion we will explore these aspects now let us straight away come to Rene Descartes the celebrated father of modern philosophy one of the most important philosophers probably the most important philosopher after Aristotle in the western world according to many thinkers. The question for Descartes is the following how to attain philosophical truth by the use of reason. So, the paramount role reason place is asserted taken for granted. So, his question is how to attain philosophical truth by the use of reason and then how do I get clear and distinct knowledge according to him genuine knowledge should be clear and distinct. So, how is it possible now when we consider the broader objectives of Cartesian philosophy he would rather look for developing a system of true propositions in which nothing is presupposed which is not self evident and indubitable there should not be any presuppositions the beginning of knowledge the starting point of knowledge should be self evident and indubitable it should be absolutely certain. So, absolute certainty is the catch word. So, knowledge should be absolutely certain it should not presuppose what was not self evident and indubitable. Now, again this points to a system with very solid foundations your starting point of knowledge should be absolutely indubitable which means that they are very strong foundations and in that sense it is absolutely completely free from skepticism. Now, again to find for philosophy the certainty of a mathematical proof sometime back I mentioned about this that the kind of a certainty which we find in mathematics is not found anywhere else mathematics is absolutely certain because there are two important reasons for that one reason is that it does not depend on what is the fact in the world because the factual world is contingent since it is not depend on it does not bother about the facts in the world it is free from all contingencies it is absolute it deals with absolute certainty and also it employs deductive method where it begins with a set of self evident axioms and deduct everything from that. So, to find philosophy the certainty as mathematical proof is one of the major objectives and again to build a system of philosophy based upon intuition and deduction which will remain as certain and as imperishable as geometry. So, you can see repeatedly he refers to mathematics and geometry these are sciences which do not depend on factual reality they deal with intuition they deal with ideas which are the result of intuition. So, in that sense they are absolutely certain a very comprehensive notion of philosophy that includes metaphysics natural sciences mechanics and morals to some extent it is a very promoted approach to have a conception of knowledge that includes everything and notion of knowledge that talks about everything in this world. So, Dakar also advocates a similar conception of knowledge which is an all encompassing notion like many of his predecessors, but we can see that you know while recognizing that there is knowledge should be all encompassing it should be absolutely comprehensive at the same time he recognizes the different aspects of knowledge. So, I will come to that with the help of a figure, but before that we enumerate some of the important points number 1 it is clear and distinct the foundational belief the belief or the knowledge from where we can start all our other enquiries should be clear and distinct it is self evident to reason it is impossible to doubt it something which is impossible to be doubted. See for example, when I say that the color of this computer is black this can be legitimately doubted by another person probably either my eyes or his eyes we do not know might be defective. So, this knowledge is based on several other factors again the light in this room is another important factor. So, it depends on several other factors, but the foundational knowledge which Dakar talks about should not be based on or dependent on other factors it should be absolutely independent and it would be impossible to doubt it. Number 2 it is certainty must be ultimate and not dependent upon the certainty of any other belief this is what I said it should be absolutely independent and number 3 it must be about something which exists hence it is possible to deduce from its belief about the existence of other thing it should be the existence of something and once you have that something that exists then from that you can deduct everything else apply the mathematical detection the method of mathematical detection and deduct everything else. So, this in this way you can build up a system of knowledge which is absolutely certain foundation or the beginning should be absolutely certain and it should employ the method of mathematical detection. So, that you can you will get a system a system of knowledge which is absolutely certain and now the question is how to arrive at foundational beliefs here Dakar employs what is known as a method of doubt. Modernity challenges all beliefs systems and methods of knowledge whatever is available to us all that is given by the tradition by our predecessors all our predecessors believed to be true and valid are questioned by modern philosophers doubt everything in order to arrive at absolute certainty that is another slogan of modernity as far as Dakar is concerned you should employ this doubt you should not trust anything you should not believe anything blindly doubt everything that can be doubted finally, you might reach a point where it is not possible to doubt and that point is probably your ultimate starting point again this application of this method is known as methodical or methodological skepticism. The use of doubt methodically in order to arrive at true knowledge which is beyond doubt. So, employment doubt in order to reach a point which is indubitable to reach a point which is beyond all doubts. Now, let us have a look at this figure here is a tree and this tree is known as the tree of wisdom. So, this is where of what I said he is presenting a very comprehensive conception of knowledge here the roots are metaphysics. So, metaphysics according to him is the roots from it is from the roots you get the nourishment a tree derives its nourishment from the roots and it is the roots which situates the tree firmly on the ground. So, in that sense they are the foundations now comes the trunk the trunk is constituted of physics physical sciences or physics and the tree of knowledge will have three important branches branch one is medicine branch two is mechanics and branch three is morals. So, everything else all human other human concerns fall under one of these three this is Cartesian conception of wisdom of human knowledge systems. Now, science reason and wisdom. So, we have seen these terms we began this lecture by pointing out the importance of science science gaining importance in human culture human society then simultaneously the notion of reason also being prominent and then naturally the conception of wisdom all the sciences taken together are identical with human wisdom which always remains one and the same I have just mentioned a very peculiar Cartesian conception of human knowledge as I mentioned he has a very comprehensive notion all encompassing conception. So, he says that all the sciences taken together are identical with the human wisdom which always remains one and the same and then there is only one kind of knowledge certain and evident knowledge absolutely certain and self evident kind of knowledge others other pieces of information are mere opinions I can have opinion about many things I can say that this room is warm, but that could be my opinion another person who is sitting in this room might feel that it is not warm there is only then ultimately there is only one science though it possesses interconnected branches. So, this is what I have shown with the help of that figure. So, basically only one science and there are different branches to this science this is typical of early modernity's conception of knowledge which later on is changed once we discuss Immanuel can we can see that you know one of the major concerns in Kantian philosophy is the segmentation of human society or segmentation of knowledge. Now, let us see some of the basic assumptions about human rationality or reason this is from Descartes book very famous celebrated book discourse on method he says that reason is the most evanly distributed thing in the world good sense or reason is the ability to judge and distinguish true from the false. So, it is a very peculiar and unique and universally present human ability it is there in all human beings and it is very unique because it enables human beings to distinguish between what is true and what is false it is equally distributed this is another very interesting observation of Descartes we cannot say that some people are more rational and some people are less rational probably some people fail to employ the rationality in the sense some others could do that that is only a failure which depends on certain conditions once those conditions are either met or removed everyone should be able to employ that reason this is fundamental Kantian assumption see modernity is very progressive in that sense it identifies a universal feature or a universal faculty that determines the very fact that we are humans and it recognizes the presence of this faculty in all human beings irrespective of whether you are a European or an American or an African or a nation it is the only thing that makes us human and differentiates as from animals and again hence it is entirely present in each of us then now we will raise the question of method because we have been discussing about we have been mentioning about this whole notion of method from the beginning. So, reason is the means to acquire a clear and certain knowledge of all that is useful in life. So, I have mentioned in the previous slide that it is the ability to judge and distinguish the true from the false now what I am saying is it is the means to acquire a clear and certain knowledge of all that is useful in life. So, I would remind you about first of second slide in which I have shown Descartes objectives Descartes says that how to get clear and distinct knowledge about everything that is one of his primary concerns and here he says that reason enables us to do that that is one reason why the one reason for the superiority of reason over common sense and other things is that reason employs a method a definite method which everyone can follow which can be universally followed where to search for a method that is a question and here these are very important questions in modern philosophy. Philosophy consists of an organically connected system of scientifically established truth this we have already seen if that is a case then we have to deal with absolutely certain and clear knowledge truths are ordered where the mind passes from fundamental self evident truths to other evident truths implied by the former. So, since we are dealing with the question of method what should be the method the method aims at arriving at absolute certainty which we have already seen and explain what it is now how is it done with the employment of a method what is this method how does it proceed it says that truths are ordered where the mind passes from fundamental self evident truths to other evident truths implied by the former. So, what you basically do is you deduct you have a self evident starting point from there you deduct the second another proposition since the first one is absolutely self evident and the second one is a derivative from the first the second one is also bound to be absolutely self evident and from there another one in this way you develop a whole system of knowledge the whole system of science which is self evident and absolutely certain such truths are present in mathematics. So, mathematics in that sense is an ideal science for Dakar as well. Now, what is the method of mathematics I have already mentioned since there is only one science method must be common hence there can be only one scientific method since the method which is applicable in mathematics the most rewarding method it must be the method of all sciences. This is the fundamental contention of Dakar and the deductive method. Now, what is so peculiar to the Cartesian approach? Dakar says that what he does is he broke with the past we have seen the past has to be doubted it is given to us, but I am not taking it as such. So, there is a break with the past and start again from the beginning without trusting the authority of any previous philosophy. So, modern philosophy envisages a new beginning with Rekat opposed to the Greeks and the Aristotelians distance from the scholastics these are all predecessors previous thinkers and there is a disbelief in past philosophers attached little to book learning in general because basically if you read and try to understand the philosophical positions of other philosophers you are a book verb you are basically focusing on book learning, but Dakar says that I am going to discard all the books I am going to learn it directly from nature. How do I do that? By employing a faculty which I have by virtue of being a human being I possess this faculty the faculty of reason by the employment of this faculty I am going to encounter nature directly reality directly and try to understand it. When you talk about the conception of absolutely certain knowledge what is your major obstacle? Because we have been talking about this absolutely certain knowledge and we have mentioned that such knowledge is possible only when you have when you apply a method, but what is that knowledge and when you talk about it there is definitely we encounter an obstacle by skepticism there is no certainty in what we construe as knowledge. Skeptics would doubt everything I mean they would you say that I am sitting and speaking they would say that what is the certainty that you sit here and speak you might be dreaming you might be sleeping and dreaming that you are engaging a lecture you are here sitting in front of your computer and a camera all these could be a dream I could be sleeping and dreaming. So, skepticism is a valid philosophical it appears to be a valid philosophical position which is which cannot be defeated. Most of our knowledge is based on uncertain assumptions, customs and conventions this is another factor we depended lot on them we are quite unreflective about the very important roles these assumptions customs and conventions play in our life. And there are no strong foundations hence to systematically doubt all that could possibly be doubted this is what a method an approach which Descartes finally adopts that I should systematically doubt all that could possibly be doubted this would take us to certain knowledge. So, at the end of it when you doubt everything finally, you reach a point where something is left which you cannot doubt that is the absolutely certain knowledge. So, this conception of absolute knowledge certain knowledge this conception would be incomplete if you do not explain or if you have no clue how to arrive it. So, the method of doubt is employed for that. So, the methodological skepticism the way in which it is being designated is employed in order to arrive at this absolutely certain knowledge. And let us see the Cartesian path what Descartes does is not to believe too firmly in anything to which I had been persuaded only by example and custom. So, that is the first thing not to believe in anything which I had been persuaded only by example or custom your reason has to be convinced that something is true. So, Descartes says thus I freed myself little by little from many errors which can dim or natural right and even make us less able to listen to reason there he compares reason with natural light. And all these factors customs traditions examples all what we have gained from our predecessors everything are factors that will dim this natural light. So, he highlights importance of this natural light it is employment and how to make it possible that is a real concern. Again he says, but after I had spent several years thus studying the book of the world and trying to get some experience I one day resolved to study my own self. And to use all the powers of my mind to choose the path I should follow which was much more successful it seems to me than if I had never left my country or my books. So, he has decided to turn his attention to himself because that is the most certain thing in one sense to turn your attention towards one yourself rather than looking around you. So, these are the four precepts to be followed in Cartesian method I will read out them this is the gist of Cartesian methodology or Cartesian approach to knowledge how does they arrive at it. Number one never accept anything as true which we could not accept as obviously true which means it should be self evident it should be intubatable absolutely beyond doubt to carefully avoid impulsiveness and prejudice. So, we have an impulse to believe in certain things see for example, when I say that there are two there are five two blights in this room and this is a statement which depends on the sense of observation. And I have an impulse to believe in this sense of observation, but the cuts reminds us that it could be false it could not be true because you might be even dreaming that possibility cannot be avoided. So, anything any information that comes through sensations can be genuinely doubted. So, and avoid impulsiveness and prejudice and to include nothing in our conclusions, but whatever was so clearly presented to our mind what we could have no reason to doubt it. So, something is treated as valid knowledge only if it is intubatable only if reason does not have any or rather reason could not doubt it. Number two divide each of the problems we examine in as many parts as we could as many as should be necessary to solve them. So, this is again the method of analysis you have a complex problem you divide it into different simple problems and try to solve it. Number three develop thoughts in order beginning with the simplest and easiest to understand matters in order to reach by degrees little by little to the most complex knowledge assuming an orderliness among them which did not at all naturally seem to follow one from the other. So, here the method suggests that one has to go from one after the other take the easiest and the simplest as your beginning as a starting point and then from there gradually move on to the next which would be equally easiest and obvious now. Since the first one is understood it is easier for us to understand the second one third one fourth one and then like that you develop a whole system of knowledge with the application of mathematical method. First one make enumeration so complete and reviews so general that we could be assured that we are not omitted anything. So, these four concepts would in one sense summarize Descartes conception of the employment of reason it also suggests how a methodology should actually work actually be employed and these are the meditations which Descartes has written meditation one deals with the things of which we made out meditation two of the nature of the human mind and that it is more easily known than the body meditation three deals with God that he exist meditation for concerning the true and the false meditation five concerning the essence of material things and again concerning God that he exist meditation six concerning the existence of material things and the real distinction between mind and body. So, we will start with meditation one to understand this two stages and the skepticism in regard to the senses and the refutation of radical skepticism we have already discussed this the first aspect that you should doubt everything that can be doubted skepticism or doubt is being employed as a method and the second aspect is the second stage is you reach a stage where this radical skepticism itself is overcome. So, doubt is employed in order to arrive at something which is indubitable doubt everything that can be doubted in order to reach the indubitable that is the proposition and again this indubitable point is a starting point of all knowledge that is the foundation of all knowledge. So, here I quote Descartes I was convinced of the necessity of undertaking once in my life to rid myself of all the opinions I had adopted and of commencing anew the work of building from the foundation if I desire to establish a firm and abiding superstructure in the sciences. So, this is the precondition and we can see that in that sense Descartes represents reflects that the very spirit of modernity not to accept anything that is given there is a fundamental skepticism towards authority and the assertion and affirmation of the power of reason human rationality. When you talk about skepticism can I doubt the fact that I am in this place sit I have already mentioned this that can I doubt the fact that I am sitting in front of this camera delivering a lecture. Similarly, Descartes says that I am sitting in this place seated by the fire clothed in a winter dressing gown that I hold in my hands the piece of paper with other intimations of the same nature I may be in a state of insanity with deserted brain it could be possible I could be a schizophrenic a schizophrenic could see things which are not there actually. So, what is the guarantee that I am not a brain in a vat or a schizophrenic I may be dreaming I could be deceived in my sleep by illusions. So, all these are possibilities that would strengthen a case for skepticism again another possibility is that God may cause me to make mistakes or an evil demon may be misleading me that is all possible there is a super power that controls all my thinking all my activities and that super power might be controlling me might be deceiving me there could be a God or a demon who is deceiving me may be all the things which I see are false and fictitious these objects I perceive may not exist I suppose that I possess no senses body figure extension motion and plays are merely fictions of my mind everything can be doubted if a schizophrenic can see things which are actually not seen by others who is right here can you deny the schizophrenic a reality which is there in front of him which he experiences he experiences it. So, one can seriously doubt if one can seriously doubt that one can seriously doubt any piece of information one derives from observation. So, body figure extension everything can be doubted and the process of doubt believes of sense perceptions believes in material things or the belief that a physical world exist as they are based upon sense perception. So, you can genuinely doubt the existence of a physical world outside your what you see in front of you. Beliefs in the natural sciences beliefs based upon sense all these beliefs natural sciences also talks about lot of things, but all those things are based upon sense perception believes in mathematics the domain of certainties even here I can doubt whether I am being deceived by an evil demon is it possible that I am always deceived. So, that is a terrible confusion a skeptic could have that everything can be doubted anything can be doubted there is nothing that one can not doubt and here this cannot go on like this. So, the cart comes with a solution to the problem in order to counter skepticism he says that I cannot doubt my existence because I doubt see I can doubt everything in front of me I can doubt everything, but there is one thing which I cannot doubt is the fact that I am doubting since the fact that I am doubting I should exist. So, that is the Cartesian approach every time I doubt I must exist to doubt even if a being which with the highest power and the deepest cunning may be constantly employing all is ingenuity in deceiving me I must exist since I am deceived in order to be deceived I must exist then the fact that I am in doubt cannot be doubted I therefore, exist because I think this is the famous celebrated Kojito ergo soon I I think therefore, I exist I think therefore, I am Kojito ergo soon the fact that I am doubting and doubting is a form of thinking and thinking implies a thinker or a thinking thing and that thinking thing should exist I am that thinking thing since I am doubting. So, I exist as a thinking thing at the absolutely certain self evident and indubitable first principle in Cartesian philosophy the only necessary truth is I think Kojito ergo soon I think therefore, I am I think I am I exist are necessarily true each time it is expressed by me or conceived in my mind I am and I exist are certain as often as I think if I cease to think then I should at the same time cease to be. So, this is the discovery of the Kojito is the Zenith is the concluding part of skepticism the Kojito is the self evident object that exist self evident to reason and is indubitable one cannot escape the Kojito by doubting it every time I doubt I affirm its existence. So, the existence of the mind existence of the thinking substance is being arrived at asserted indubitably and for Descartes that is a starting point which is indubitable it independent of any more ultimate truth it is not inferred from the more ultimate truth or who think exist it refers to the existing world the Kojito refers to me who exist as a thinking thing. Now, the questions are what is this I what am I I know that I exist because I think hence I am only a thinking thing that is a mind it is a thing that doubts imagines understands affirms denies conceives perceives wills refuses etcetera. So, Descartes methodology has actually begun with the question of doubt or rather I would put it in this way to summarize the first point is he has a very peculiar conception of knowledge knowledge should be absolutely universal absolutely certain it should be indubitable and he has a very comprehensive conception of knowledge a very comprehensive conception of science where it includes everything all aspects of knowledge is included under one umbrella which is called science and this knowledge should be absolutely certain it is a system of absolutely certain knowledge, but the question is how do you arrive at this system you arrive at this system by starting with a self evident absolutely self evident indubitable point of knowledge. Once you have that indubitable point of knowledge you can deduct you can apply mathematical deduction and deduce the remaining prepositions and finally, arrive at a complex system of prepositions which we today understand as knowledge. Now, how do you do that for that Descartes employs a method I am just summarizing that employs a method the method of doubt which is a methodological or methodical skepticism where you doubt everything that can be doubted. So, in this process basically Descartes doubts everything fundamental skepticism with regard to the abilities and powers of your senses this is what Descartes does and in this process he arrives at a point which is indubitable that is the fact that I am doubting and since I doubt and since doubt is to think and to think implies a thinker I must exist as a thinking think Kojito ergosum I think therefore, I am. So, this is where we stop today this lecture we will stop here and we will continue with the next topic in the coming lectures. Now, the important questions to be addressed are as a domain of reality we know that you know the these philosophers always consider that the domain of reality includes three things God mind and body. Now, we have talked about the mind the Kojito the existence of the mind is indubitably proved now the second one now the question is your mind is there, but if you have so far proved only the existence of your mind, but this entire reality in front of you could be a mere creation of your mind. So, this leads to a kind of solipsism me and my mind alone exist. So, how to counter this and how to establish the fact that a world an external world of objects of nature exist these are the next questions which we will take up in the next lecture. Till then thank you.