Thales of MiletusHe was traditionally regarded as the first Western philosopher and mathematician. He was the founder of the Milesian School of natural philosophy, and the teacher of Anaximander. He is remembered primarily for his cosmology based on water as the essence of all matter, with Earth a flat disk floating on a vast sea.
AnaximanderAnaximander explained the origin of the universe with the theory of 'apeiron' (the “infinite,” “unlimited,” or “indefinite”), rather than from a particular element, such as water—which as Thales had held. According to Anaximander, "The universe is boundless but consists of a primary substance".
AnaximenesIn physical sciences, he was the first Greek to distinguish clearly between planets and stars, and he used his principles to account for various natural phenomena, such as thunder and lightning, rainbows, earthquakes, etc.
PythagorasHe is the founder of Pythagoreanism. He himself came up with the theory that numbers are of great importance for understanding the natural world, and he studied the role of numbers in music.
SocratesHe was an Athenian Philosopher whose questions and opinions clashed with the current course of Athenian politics and society. He was also best known as a questioner of everything and everyone.
Period: 469 BCE to 399 BCE
SocratesHe's known for his Socratic Method, which is a method of hypothesis elimination, in that better hypotheses are found by steadily identifying and eliminating those that lead to contradictions. He worked to critically examine the foundational beliefs that were common in Greece during his time, and encouraged other citizens to do so as well. Unfortunately, he was suspected for corrupting the youth and disbelieving in the gods of the city, which caused him to be sentenced to death.
PlatoHe's a Socratic philosopher and the teacher of Aristotle. He also ranks among the greatest philosophers in the world, and is viewed by many scholars as the most important Philosopher of Western civilization.
Period: 428 BCE to 348 BCE
PlatoPlato’s main concern is to challenge the views most people have about goodness, for it is here that they go disastrously wrong in trying to live happy lives. Most people think that virtue is a minor good, or even an impediment to living a happy life. Plato considers this to be incorrect; it is only by being virtuous that we can hope to be happy.
AristotleHe was known as the "The First
Teacher;” in the West, he was “The Philosopher.” He was a student of Plato for twenty years but is famous for rejecting Plato's Theory of Forms.
Period: 384 BCE to 322 BCE
AristotleAristotle argued that virtues are good habits that we acquire, which regulate our
emotions. For example, in response to a natural feeling of fear, one should develop the virtue of courage, which allows a person to be firm when facing danger or fear.
Thomas HobbesHe was an English philosopher and was considered to be one of the founders of modern political philosophy. He is famous for his early and elaborate development of what has come to be known as “social contract theory”, the method of justifying political principles or arrangements by appeal to the agreement that would be made among suitably situated rational, free, and equal persons.