There were several thinkers who did in fact develop basic theories about real, how we can know things, and how we should live. Since Socrates never wrote anything himself we must turn to Plato for any ideas about what he thought. Let’s take a look art the ideas of the most well-known presocratic thinkers. I should note that what we know if these thinkers is often very fragmentary and vague. One wonders what it was about the early Greek culture that created such thinkers
PHILOSOPHERS BEFORE SOCRATES First, there was Thales who lived around 600 BCE. Thales originally came from the town of Miletus near what is today the Turkish coast. He was a very diverse and creative thinker. He figured out the height of the pyramids by measuring their shadows them to the shadows of objects whose height was already known. He also actually predicted the eclipse of the sun on May 28, 585 BCE, but it is not known how he did so. It is also said that Thales knowing something about farming bought up all the local wine presses in an off year and profited greatly when the bumper harvest came around the next year. He used this to answer the criticisms that philosophers were useless.
Thales major philosophical contribution, however, was his theory that the basic stuff of reality is water. From his careful observations of the how things grow and change into other forms of life he concluded that water lies at the very heart of reality. In this sense he may have been the first actual scientist, making physical observations and drawing logical conclusions therefrom.
One of Thales’ pupils, Anaximander, pressed his teacher’s observations yet further and concluded there is a more fundamental element in reality that constitutes it’s basic nature. He called this more basic reality the “indeterminate boundless.” He claimed that within and all around all such things as water there is a more fundamental substance or reality out of which all others arise. Speculating that all other aspects features of the natural world arise from this “unbounded”, Anaximander actually gave rise to the origin of science as we think of it. The third
Milesian thinker was in turn a student of Anaximander, namely Anaximenes, who developed his teacher’s ideas by suggesting that this “unbounded” is actually air
A quite different approach to this question of the origins and nature of reality was developed by a group of thinkers on the island of Samos who came to be called the “Pythagoreans” after its founder the mathematician Pythagoras. This thinker, along with his followers, sought to explain the nature of reality as a direct function of mathematical relationships. Numbers, according to Pythagoras, lie at the heart of all aspects of reality. This group of thinkers, along with their leader, lived around 500 BCE. They even attached some sort of religious significance their study of numerical relations.
Pythagoras actually assigned religious meaning to the various aspects and complex derivations of mathematical study. Pythagoras himself is actually credited with discovering the theorem given his name, the “Pythagorean Theorem”, which establishes the truth that the square of the hypotenuse of a right angle triangle is equal to that of the sides of the other two sides. Pythagoras claimed that such numerical relationships are the key to understanding all of reality. Pythagoreans actually claimed to have discovered the numerical basis of all reality, including life. Their influence on Plato is clear throughout the latter’s works.
While these early thinkers sought to base the understanding of reality on what is unchangeable about it, Heraclitus did just the opposite. He claimed that the nature of reality is actually to be found in change or what he called “flux”. He lived in the city of Ephesus around 500 BCE. Heraclitus chose “fire” as the symbol of the basic nature of reality because fire is always changing while yet remaining the same fire. Herein he saw the basic pattern of both nature and history. Because we have very few fragments of his works, the pivot of his cryptic thought remains something of a mystery. Thus he is often referred to as “Heraclitus the dark.”
At the opposite end of the spectrum from Heraclitus stands Parmenides, a thinker who claimed that there is no such thing as change, that reality consists of a comic “Oneness” with no diversity nor change. For him change and diversity are illusionary. Parmenides lived around 510 BCE and was extremely influential on Plato. His work was further developed by his disciple Zeno, who is famous for having developed various logical paradoxes by means of which he claimed to proves the fallibility of sense perception and change. The most famous of these is his argument that if a turtle starts out with even the tiniest lead over the rabbit the rabbit can never catch up because with each inch of his progress the turtle would always get a bit further ahead, ad infinitum.
Next along came Empedocles who lived in Sicily during the 400s BCE. He was in a way the first “Atomistic” thinker, for he claimed that far from all things being any sort of extension of some ”Great One”, reality is made up of an infinite number of tiny particles, thus paving the way for a more “atomistic” approach to thinking about reality. Empedocles was followed by Anaxagoras who added the idea that a great mind, Nous, controls the activity of the One and all other aspects of reality. His thought led the way for later atomistic thinkers, such as Leucippus and Democritus, to develop more sophisticated versions of atomism in which cosmic thought directed all the movement and activity of individual atoms. These thinkers laid the groundwork for the modern atomic theory of Issac Newton.