The ancient Greek philosophers gave us the basic categories of philosophy, beginning with metaphysics. Metaphysics is the part of philosophy that asks questions such as “What is the world made of?" and "What is the ultimate substance of all reality?”

In fact, the ancient Greeks were among the first to suggest that there is a “true” reality (noumenon) under the “apparent” reality (phenomenon), an “unseen real” beneath the “unreal seen.” The question is, what is this true reality? Is it matter and energy, i.e. something physical? This is called materialism. Or something more spiritual or mental, such as ideas or ideals? This is called idealism. Materialism and idealism constitute the two extreme answers. Later, we will explore some other possibilities.

A second aspect of philosophy is epistemology. Epistemology is the philosophy of knowledge: How do we know what is true or false, what is real or not? Can we know anything for certain, or is it ultimately hopeless?

Again, the Greeks outlined two opposing approaches to the problem of knowledge. One is called empiricism, which says that all knowledge comes through the senses. The other is called rationalism, which says that knowledge is a matter of reason, thought. There are other answers in epistemology as well. In fact, empiricism and rationalism have never been entirely exclusive.

The third aspect of philosophy that we will be concerned with is ethics. Ethics is the philosophical understanding of good and bad, right and wrong. It is often called morality, and most consider the two words synonymous. After all, ethics comes from ethos, which is Greek for customs, and morality comes from mores, which is Latin for customs!

As we shall see, ethics is the most difficult of the three aspects of philosophy. For the present, we might want to differentiate the extremes of hedonism and cynicism. Hedonism says that good and bad come down to what I like and what I don’t like, what gives me pleasure and what gives me pain. Cynicism says that world is essentially evil, and we can only work at distancing ourselves from it and moving towards the ultimate good, which is God.

There are many other aspects of philosophy -- logic, for example, and esthetics, the study of beauty. But metaphysics, epistemology, and ethics are sufficient for now.