Everyone needs philosophy, was Ayn Rand's answer to that question, which she gave in an address to the graduating class at West Point in 1974. Everyone lives according to some philosophy, whether they realize it or not.
As Ayn Rand said in her address:
. . . the principles you accept (consciously or subconsciously) may clash with or contradict one another; they, too, have to be integrated. What integrates them? Philosophy. A philosophic system is an integrated view of existence. As a human being, you have no choice about the fact that you need a philosophy. Your only choice is whether you define your philosophy by a conscious, rational, disciplined process of thought and scrupulously logical deliberation - or let your subconscious accumulate a junk heap of unwarranted conclusions, false generalizations, undefined contradictions, undigested slogans, unidentified wishes, doubts and fears, thrown together by chance, but integrated by your subconscious into a kind of mongrel philosophy and fused into a single, solid weight: self-doubt, like a ball and chain in the place where your mind's wings should have grown.
So if you want to know yourself better, if you want to gain conscious control of your life, your decisions, your judgments, if you want to understand what causes your emotions, you must learn to engage in introspection.
Do you, for example, hate profit-chasing Big Oil executives? Your answer to that question, whether negative or affirmative, reveals a part of your implicit philosophy. If you dislike the desire for profit, ask yourself why. Perhaps you believe profits are immoral. Dig down another step: why do you hold that profits are immoral? Some will answer: because the desire for profit is selfish. For these people, this answer reveals that altruism is their moral philosophy, their ethics. Altruism is the moral code which holds that service to others -selflessness - is the good, and selfishness is the evil. Think Mother Teresa, the most well known altruist in recent times.
Anything opposed to altruism, such as the pursuit of profit, is immoral to an altruist. Dig further into your philosophy and ask yourself why altruism is your moral philosophy. In pursuing these elusive answers, you will be getting at your philosophical premises.
The purpose of this exercise in self-examination is to become aware of the philosophical premises that have been guiding your life subconsciously - without your authorization, so to speak. Most people will find some of the premises they have adopted, somewhere along the way, are not supportable upon close examination. Then discard them, and replace them with premises you can support.
After a lifetime of persistent self-examination, and of pestering others to do the same, the Greek philosopher, Socrates, was convicted of corrupting the minds of the young. He faced the death penalty, but it was suggested he might be allowed to live if he would accept exile, and cease to be the annoying philosophical gadfly he admitted to being. He refused the offer. The unexamined life, he said, is not worth living.