The story of philosophy begins in Greece. The ancient Greeks provided the world with some of its greatest philosophers. The most famous are Plato (427-347BC) and Aristotle (384-322BC), and Plato's teacher Socrates (469-399 BC). Before Socrates came the first philosophers, the pre-Socratics (that is those who came before Socrates).
The earliest pre-Socratic philosophers were curious about the nature of the world as a whole. They believed that there was one kind of 'stuff' out of which the whole world was made. Thales (6th century BC) said that all things were made of water. No doubt he had his own reasons for saying this but we know little about them. One thing is certain - he had no microscopes to help him in reaching his conclusions.
Other thinkers put forward other claims about the basic stuff of the world. Anaximenes (6th century BC) said it was air. Heraclitus (6th century BC) did not feel so strongly that there was one basic stuff out of which all things are made. He was struck by the way the world was constantly changing. He said 'You can never step into the same river twice', meaning that although the river may look the same there is always a new body of water flowing through it. But he also felt that things changed in accordance with a definite law. Fire, according to Heraclitus, is the most important substance in the world, since it is the main cause of change.
Pythagoras (570-500BC) did not think that the clue to understanding the universe lay in finding one basic stuff of which all things are made. He claimed that measurement or number was the real key to understanding, and he made many striking discoveries about the numerical properties of things. Pythagoras also claimed that he knew the best way to live. He taught that in each human being there is a soul; when a man dies his soul goes into another body, perhaps that of an animal. Because of these beliefs (similar to those of the Hindus on reincarnation), Pythagoras claimed that we should spend our lives caring for that part of us which never dies -the soul. Pythagoras had many followers and influenced later thinkers.
Evidence of our senses
The views of the earliest pre-Socratics on the nature of the universe raised one of the most discussed philosophical questions: what is the best way of finding out about the world? In particular, how much notice should we take of the evidence of our senses? The things we see, touch, hear and feel? We may think that the world is made up of one basic stuff, but can we be sure that it is, if we have not checked our belief against what we can see and feel?
Parmenides (5th century BC) and many later philosophers thought that we could work out the true nature of the world just by thinking about it. But we must think about it in one particular way. We must start with a premise or premises (that is propositions agreed after reasoning), which we know to be true, and only allow ourselves to believe things which must be true, if the premises are true. In this way we can arrive at certainty about the world by thought alone. Parmenides believed that he had himself reached the truth and he thought he had proved that change and movement were impossible. He was so convinced that the conclusion of his proof was true, that he could not see how to believe the opposite, even if he was tempted to do so by what he saw.
Parmenides's follower, Zeno (5th century BC), who became famous for his paradoxes (sayings which contradict most people's opinions), also argued that, in his opinion, motion was impossible.
After Parmenides's disturbing claims, some philosophers called atomists, led by Democritus (5th century BC), tried to 'save appearances'. We see change and movement, they said, so there must be change and movement. The atomists concluded that the world was made up not of one un-moving spherical mass, as Parmenides had suggested, but of millions of tiny atoms, which could change position among themselves and thus make up new things in time.
The pre-Socratic philosophers were mainly interested in the universe as a whole, and in man only in so far as he was part of that whole. There was much disagreement among them, and it was not easy for them to settle their disputes without the aid of scientific instruments.
The Rule Of Law
Soon a new interest began to absorb Greek thinkers. The Greeks came into contact with people of many different lands, with very different ways of living from their own. This caused them to ask whether any law or rule of conduct was better than any other. Why should we do what the law tells us to do? This was the beginning of political and ethical philosophy.
A group of men called sophists (wise men) tried to tackle these new questions. Protagoras (485-411BC), the most famous sophist, argued that if everyone obeyed some laws the life of each man, even the strongest, would be improved. So each man should be law-abiding. Protagoras also thought that some laws were better than others. A state could have bad laws but in general some law was better than no law.
The sophists took an important part in the education of the Greeks. There were no high schools or universities in their time. The philosophers took the place of school teachers; they accepted fees for their teaching and became rich. One of the things they taught was the art of making speeches in public. Often they stressed the importance of making one's audience think one was right, rather than actually being right.
In this respect the Athenian philosopher Socrates was very different from the sophists. He took no fees and lived in poverty. He was not interested in sounding as if he had knowledge, but actually in finding knowledge. Socrates shared with the sophists their interest in the conduct of human life, rather than the workings of nature as a whole. He studied the pre-Socratic philosophies but soon turned to his own questions and found his own way of answering them.
One of Socrates's main questions was, 'How would a really good man live his life?' It seemed to him quite clear that one could find out what sort of life would be lived by a really good man. More important, we can only be truly good, Socrates thought, if we know clearly and definitely what is good. He believed that no one does wrong willingly. We all do what we think is right. But in order constantly to do right, we must know what really is right. So Socrates began, to try to find out what makes an action right or good.
He went about his search in his own special way, which won him enemies as well as admirers. He did not begin by telling people what he thought goodness was, but tried to find out what they thought. He questioned poets, politicians and all kinds of men. 'What makes an action right?' he asked. 'What do we mean by "right-ness" or "goodness"?' By such questions Socrates tried to make clear people's ideas about right and wrong. He tried to find out the exact meanings of certain important words which, without pausing to think what they mean, we all use freely in daily life. But Socrates made enemies in the course of his search, and was brought to trial by them and condemned to death for false teachings. Yet he died calmly, convinced that no harm could come to a man who had done his duty.
One of Socrates's pupils and admirers devoted his life to developing his master's teaching. This was Plato, who had once planned to become a politician, but changed his mind when he saw that a man like Socrates could be condemned to death in the courts. Instead he devoted himself to philosophy and founded the Academy at Athens.
Many of Plato's books, unlike the works of the earlier philosophers, have survived till today. These take the form of imaginary conversations, or dialogues, between various people. Socrates is often one of the characters and Plato gives us examples of the historical Socrates's method. The earliest dialogues are searches for the meanings of terms like 'courage' or 'justice', which often reach no definite conclusion. But gradually Plato developed his own philosophy, still in connection with the same problems.
What is special about Plato's thinking is that he felt sure that goodness was some one thing which existed by itself, quite apart from the many particular good things. He argued that goodness itself was something unchanging and permanent. A good man might perhaps change and become bad. Everything around us is constantly changing. But how can goodness itself change? The nature of goodness is always the same.
One aim of the philosopher, according to Plato, is to discover the nature of goodness. Without goodness we could be neither good men nor good rulers. This is very like Socrates's view that in order to be good we must be clear about what goodness is; but Socrates did not talk about goodness as something eternal and unchanging, as Plato does.
Perhaps noting the difficulties Socrates had in discovering the nature of goodness, Plato felt that a long training was necessary before one was ready to discover its true nature. He describes the education that he thinks a philosopher should have in his most famous book The Republic.
It should begin with training in music, literature and gymnastics - to take care of both mind and body. The next stage was a thorough study of mathematics. The reason for this is that in mathematics, although we draw particular triangles from which to work out our conclusions, in fact our conclusions are not about these particular figures. What we draw and see are only imperfect examples. What we learn about is the nature of triangularity itself. This is the last stage of the way, before philosophers can turn to the study of non-mathematical forms: this will not be before they are fifty years of age. Thus Plato saw philosophy as a long and hard task, needing a training which few men would be clever enough to complete.
In The Republic Plato also describes what he thinks would be a perfect city-state. In this, the rulers are philosophers who have reached the goal of their education - knowledge of goodness itself. Only with this knowledge, thought Plato, could a man know how to rule. How otherwise could he be sure what was good for the city-state ? Plato did not think well of the Athenian democracy in which those who made important decisions were not experts. He believed that just as only a doctor, an expert in curing the sick, should be allowed to prescribe medicines for them, so only an expert should be allowed to govern.
Aristotle entered Plato's Academy at seventeen, and stayed for twenty years. His father was a doctor; this may help to explain the amazing scope of Aristotle's own interests. He worked and wrote on zoology and astronomy, as well as on logic, ethics, aesthetics, politics, the nature of change (in the Physics) and what he called 'first philosophy'. His writings on first philosophy were placed by his editors after the Physics, and in this way became known as the Metaphysics -which means after physics in Greek. When we talk of metaphysical theories nowadays we usually refer to theories about existence which are not based on scientific experiment.
Aristotle wrote one of the greatest books on logic. He regarded logic as the study of forms of reasoning which are the same for every subject. Aristotle made a careful study of a pattern of reasoning he called the syllogism, which is made up of a pair of premises and a conclusion. By this study Aristotle became the first really important logician.
In the period after Aristotle's death, philosophers concentrated again on the problem: how should life be lived? Their teachings were popular and well-known, more so than the teachings of most philosophers. The sciences began to be developed by other men, separately from philosophy.
Epicurus (341-270 BC) believed that men's souls did not survive their deaths, and so there was no need to spend one's life preparing the soul for life after death, as others had suggested. Epicurus noticed that all living beings seek pleasure and avoid pain. He concluded that pleasure is good for man. But he actually advised men to seek, in particular, calmness of mind. Thus the Epicureans recommended a quiet and simple life as the best one.
The Stoics said that men should not aim at pleasure or riches; they should try to make themselves as independent of other things as possible. Self-control was one main Stoic aim. The meaning of the adjective stoical reflects the Stoics' view of how to live. Theirs was a long-lived philosophy, the Roman Emperor Marcus Aurelius (AD 121-180) was a Stoic.