 What is faith? Even to begin to understand the problem of faith, one must differentiate between rational and irrational faith. By irrational faith, I understand the belief which is based on one's submission to irrational authority. In contrast, rational faith is a conviction which is rooted in one's own experience of thought or feeling. Rational faith is not primarily belief in something, but the quality of certainty and firmness which our convictions have. The process of creative thinking in any field of human endeavor often starts with what may be called a rational vision, itself a result of considerable previous study, reflective thinking and observation. When the scientist succeeds in gathering enough data or in working out a mathematical formulation to make his original vision highly plausible, he may be said to have arrived at a tentative hypothesis. A careful analysis of the hypothesis in order to discern its implications and the amassing of data which support it lead to a more adequate hypothesis and eventually perhaps to its inclusion in a wide-ranging theory. At every step from the conception of a rational vision to the formulation of a theory, faith is necessary. Faith in the vision as a rationally valid aim to pursue, faith in the hypothesis as a likely implausible proposition and faith in the final theory, at least until a general consensus about its validity has been reached. This faith is rooted in one's own experience, in the confidence in one's power of thought, observation and judgment. While a rational faith is the acceptance of something as true only because an authority or the majority say so, rational faith is rooted in an independent conviction based upon one's own productive observing and thinking in spite of the majority's opinion. In the sphere of human relations, faith is an indispensable quality of any significant friendship or love. Having faith in another person means to be certain of the reliability and unchangeability of his fundamental attitudes, of the core of his personality, of his love. By this, I do not mean that a person may not change his opinions, but that his basic motivations remain the same. That, for instance, his respect for life and human dignity is part of himself, not subject to change. In the same sense, we have faith in ourselves. We are aware of the existence of a self, of a core in our personality which is unchangeable and which persists throughout our life in spite of varying circumstances and regardless of certain changes in opinions and feelings. It is this core which is the reality behind the word, I, and on which our conviction of our own identity is based. Unless we have faith in the persistence of our self, our feeling of identity is threatened and we become dependent on other people whose approval then becomes the basis for our feeling of identity. Only the person who has faith in himself is able to be faithful to others because only he can be sure that he will be the same at a future time as he is today and therefore that he will feel and act as he now expects to. Another meaning of having faith in a person refers to the faith we have in the potentialities of others. The most rudimentary form in which this faith exists is the faith which the mother has toward her newborn baby. That it will live, grow, walk, and talk. However, the development of the child in this respect occurs with such regularity that the expectation of it does not seem to require faith. It is different with those potentialities which can fail to develop. The child's potentiality is to love, to be happy, to use his reason and more specific potentialities like artistic gifts. They are the seeds which grow and become manifest if the proper conditions for their development are given and they can be stifled if these are absent. One of the most important of these conditions is that the significant person in a child's life have faith in these potentialities. The faith in others has its culmination in faith in mankind. Like the faith in the child, it is based on the idea that the potentialities of man are such that given the proper conditions he will be capable of building a social order governed by the principles of equality, justice, and love. Man has not yet achieved the building of such an order and therefore the conviction that he can do so requires faith. But like all rational faith, this too is not wishful thinking, but based upon the evidence of the past achievements of the human race and on the inner experience of each individual, on his own experience of reason and love. The basis of rational faith is productiveness. To live by our faith means to live productively. It follows that the belief in power in the sense of domination and the use of power are the reverse of faith. There is no rational faith in power. There is submission to it or, on the other part of those who have it, the wish to keep it. While to many power seems to be the most real of all things, the history of man has proved it to be the most unstable of all human achievements. Because of the fact that faith and power are mutually exclusive, all religions and political systems which originally are built on rational faith become corrupt and eventually lose what strength they have if they rely on power or ally themselves with it. To have faith requires courage, the ability to take a risk, the readiness even to accept pain and disappointment. Whoever insists on safety and security as primary conditions of life cannot have faith. To be loved and to love need courage, the courage to judge certain values as of ultimate concern and to take the jump and stake everything on these values. Is there anything to be practiced about faith and courage? Indeed, faith can be practiced at every moment. It takes faith to bring up a child, it takes faith to fall asleep, it takes faith to begin any work. But we all are accustomed to having this kind of faith. To stick to one's judgment about a person even if public opinion or some unforeseen facts seem to invalidate it, to stick to one's convictions even though they are unpopular, all this requires faith and courage. To take the difficulties, setbacks and sorrows of life as a challenge which to overcome makes us stronger rather than as unjust punishment which should not happen to us requires faith and courage. The practice of faith and courage begins with a small details of daily life. The first step is to notice where and when one loses faith, to look through the rationalizations which are used to cover up this loss of faith, to recognize where one acts in a cowardly way and again how one rationalizes it. To recognize how every betrayal of faith weakens one and how increased weakness leads to new betrayal and so on in a vicious circle. Then one will also recognize that while one is consciously afraid of not being loved, the real though usually unconscious fear is that of loving. To love means to commit oneself without guarantee, to give oneself completely in the hope that our love will produce a love in the loved person. Love is an act of faith and whoever is of little faith is also of little love. One attitude is basic for the practice of love, activity. I have said before that by activity is not meant doing something, but an interactivity, the productive use of one's powers. Love is an activity. If I love, I am in a constant state of active concern with the loved person, but not only with him or her, for I shall become incapable of relating myself actively to the loved person if I am lazy, if I am not in a constant state of awareness, alertness, activity. Sleep is the only proper situation for inactivity. The state of awakeness is one in which laziness should have no place. The paradoxical situation with a vast number of people today is that they are half asleep when awake and half awake when asleep or when they want to sleep. To be fully awake is the condition for not being bored or being boring and indeed not to be bored or boring is one of the main conditions for loving. To be active in thought, feelings with one's eyes and ears throughout the day to avoid inner laziness, be it in the form of being receptive, hoarding or plain wasting one's time is an indispensable condition for the practice of the art of loving. The capacity to love demands a state of intensity, awakeness, enhanced vitality which can only be the result of a productive and active orientation in many other spheres of life. If one is not productive in other spheres, one is not productive in love either.