Thales of Miletus
Influence

As the first philosopher and mathematician, Thales had a profound influence on other Greek thinkers and therefore on Western history. However, due to the scarcity of sources concerning Thales and the discrepancies between the accounts given in the sources that have survived, there is a scholarly debate over the extent of the influence of Thales had and on which of the Greek philosophers and mathematicians that came after him.

The first three philosophers in the Western tradition were all cosmologists from Miletus, and Thales was the very first, followed by Anaximander, who was followed in turn by Anaximenes. They have been dubbed the Milesian school. According to the Suda, Thales had been the "teacher and kinsman" of Anaximander. Rather than water, Anaximander held all was made of apeiron or the unlimited; while Anaximenes, the successor of Anaximander, perhaps more like Thales with water, held that everything was composed of air.

John Burnet (1892) noted

Lastly, we have one admitted instance of a philosophic guild, that of the Pythagoreans. And it will be found that the hypothesis, if it is to be called by that name, of a regular organisation of scientific activity will alone explain all the facts. The development of doctrine in the hands of Thales, Anaximander, and Anaximenes, for instance, can only be understood as the elaboration of a single idea in a school with a continuous tradition.

As two of the first Greek mathematicians, Thales is also considered an influence on Pythagoras. According to Iamblichus, Pythagoras "had benefited by the instruction of Thales in many respects, but his greatest lesson had been to learn the value of saving time." Early sources report that Pythagoras, in this story a pupil of Anaximander, visited Thales as a young man, and that Thales advised him to travel to Egypt to further his philosophical and mathematical studies.

Thales was also considered the teacher of the astronomer Mandrolytus of Priene. It is possible he was also the teacher of Cleostratus of Tenedos.
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