This lecture was delivered to the graduating class of the United States Military Academy at West Point on March 6,1974. ince I am a fiction writer, let us start with a short, short story. Suppose that you are an astronaut whose spaceship gets out of control and crashes on an unknown planet. When you regain consciousness and find that you are not hurt badly, the first three questions in your mind would be: Where am I? How can I discover it? What should I do? You see unfamiliar vegetation outside, and there is air to breathe; the sunlight seems paler than you remember it and colder. You turn to look at the sky, but stop. You are struck by a sudden feeling: if you don't look, you won't have to know that you are, perhaps, too far from the earth and no return is possible; so long as you don't know it, you are free to believe what you wish-and you experience a foggy, pleasant, but somehow guilty, kind of hope. You turn to your instruments: they may be damaged, you don't know how seriously. But you stop, struck by a sudden fear: how can you trust these instruments? How can you be sure that they won't mislead you? How can you know whether they will work in a different world? You turn away from the instruments. Now you begin to wonder why you have no desire to do anything. It seems so much safer just to wait for something to turn up somehow; it is better, you tell yourself, not to rock the spaceship. Far in the distance, you see some sort of living creatures approaching, you don't know whether they are human, but they walk on two feet. They, you decide, will tell you what to do. You are never heard from again. This is fantasy, you say? You would not act like that and no astronaut ever would? Perhaps not. But this is the way most men live their lives, here, on earth. Most men spend their days struggling to evade three questions, the answers to which underlie man's every thought, feeling and action, whether he is consciously aware of it or not: Where am I? How do I know it? What should I do? By the time they are old enough to understand these questions, men believe that they know the answers. Where am I? Say, in New York City. How do I know it? It's self-evident. What should I do? Here, they are not too sure—but the usual answer is: whatever everybody does. The only trouble seems to be that they are not very active, not very confident, not very happy-and they experience, at times, a causeless fear and an undefined guilt, which they cannot explain or get rid of. They have never discovered the fact that the trouble comes from the three unanswered questions-and that there is only one science that can answer them: philosophy. Philosophy studies the fundamental nature of existence, of man, and of man's relationship to existence. As against the special sciences, which deal only with particular aspects, philosophy deals with those aspects of the universe which pertain to everything that exists. In the realm of cognition, the special sciences are the trees, but philosophy is the soil which makes the forest possible. Philosophy would not tell you, for instance, whether you are in New York City or in Zanzibar (though it would give you the means to find out). But here is what it would tell you: Are you in a universe which is ruled by natural laws and, therefore, is stable, firm, absolute-and knowable? Or are you in an incomprehensible chaos, a realm of inexplicable miracles, an unpredictable, unknowable flux, which your mind is impotent to grasp? Are the things you see around you real-or are they only an illusion? Do they exist independent of any observer—or are they created by the observer? Are they the object or the subject of man's consciousness Are they what they are—or can they be changed by a mere act of your consciousness, such as a wish? The nature of your actions-and of your ambition-will be different, according to which set of answers you come to accept. These answers are the province of metaphysics -the study of existence as such or, in Aristotle's words, of "being qua being"—the basic branch of philosophy.