The birthplace of philosophy was the seaport town of Miletus, located across the Aegean Sea from Athens, on the western shores of Ionians, and for this reason the first philosophers are called either Milesians or Ionians. By the time the Milesians philosophers began their systematic works, roughly c.585 B.C., Miletus had been a crossroads for both seaborne commerce and for cosmopolitan ideas. Its wealth made possible the leisure without which the life of art and philosophy could hardly develop, and the broad-mindedness and inquisitiveness of its people created a congenial atmosphere for the intellectual activity that was to become philosophy.
The three Ionian philosophers are Thales, Anaximander and Anaximines. These three Ionian philosophers or the first philosophers were also known as the Ionian physicists.
Thales was born in Miletus. Although the exact date of his birth is unknown, the information we have about him point to the conclusion that he began his philosophical career at the start of the c.6th B.C.
Thales is traditionally regarded as the first philosopher, and, in a way, is put forward as the prototype of the wise man. According to several testimonies, he played an important role in public and academic life; he excelled in politics, mathematics and astronomy.
About his philosophical doctrine, however, there is little information. Thales did not commit his thought to writing, and the little we know about him as a philosopher comes mainly from Aristotle. Aristotle says that Thales taught two basic philosophical ideas: that water is the first absolute principle, and that the soul is the principal motor. (History of Philosophy by Ignatius Yarza pp. 13-14)
Anaximander was born in Miletus around the year 611 B.C., and was a disciple of Thales. He wrote a book entitled On Nature. Like his master, he has a keen interest in cosmology. He differed, however, from Thales in his choice of the first principle. For Anaximander, it was not water but the ápeiron – “the infinite” or “the unlimited” – which constituted the first principle. (History of Philosophy by Ignatius Yarza p. 15)
“Anaximander, son of Praxiades, and who hailed from Milesia, was among those who affirmed that the first principle in one, moving and infinite. Successor and disciple of Thales, he said that the principle and constitutive element of the things that exist is the ápeiron. He was the one who first designated the material principle of the all things by this name.” (Simplicius, In Arist. Phys., 24,13 (DK 12 A 9)
Anaximines was born at the beginning of the 6th C.B.C., and died towards the end of the same century. Successor to Anaximander, he is the third of the Miletian philosophers. All we know about his life and scientific activity is that he authored a book, fragments of which have been handed down to us.
The first principle of Anaximines is infinite like that of Anaximander’s; however, unlike the latter, it has a definite nature. Air is the first principle for Anaximines.
“Anaximines of Miletus, son of Euristrates and companion of Anaximander, affirms together with the latter, that the substrate of everything is one and infinite. This substrate, however, is not indeterminate like that of Anaximander’s, but is of a definite nature: it is what we call air.”
Heraclitus was born in the middle of the 6th C. B.C., and died c. 480 B.C. He came from Miletus and belonged to the aristocracy. He was the last of the Ionian philosopher who remained in his country.
Testimonies about Heraclitus depict him as a conceited, proud person who despised the rest of humanity because of their blindness to the truth of his teachings, and who subjected the doctrines of the ancient poets and philosophers to harsh criticism. We can, therefore, imagine him as a philosopher who was conscious of the novelty and significance of his teaching, but who alienated himself from the rest of men on his account. His philosophy is found in a book entitled On Nature, several fragments of which have been preserved. In spite of the material available about Heraclitus, it is not easy to determine the exact nature of his thought on account of the cryptic, almost occult, character of his writings – a trait which earned for him the epithet “the obscure one” even during his lifetime. This is perhaps one of the reasons why Plato and Aristotle make no special effort to penetrate his thought, describing it simply as an exaggerated relativism – a description which has been given to his philosophy.
Heraclitus affirmed that everything is in constant flux: panta rei, “everything changes.” We know this from his own writings. He said, for example, that “it is certainly not possible to enter twice into the same river.” It is also attested to by later philosophers like Plato: “Heraclitus says somewhere that all things change and that nothing is at rest.” This doctrine of universal change was an original contribution of Heraclitus to the history of the pre-Socratic thought.