Thales of Miletus, c. 624 – c. 546 BC was a Greek philosopher, mathematician, and astronomer who influenced much of later classical Greek and western thought
He was one of the pre-Socratic philosophers, who were concerned with “the essence of things. They were named physiologoi (φυσιολόγοι), physical or natural philosophers or physikoi (physicists) because they sought natural explanations for phenomena, as opposed to the earlier theologoi (theologians), whose explanations looked to the supernatural.
The pre-Socratic philosophers were asking:
- From where does everything come?
- From what is everything created?
- How do we explain the plurality of things found in nature?
- How might we describe nature mathematically?
Thales’ hypothesised that the originating principle of nature and matter was a single substance: water. Moreover, rather than assuming that earthquakes were the result of the whims of divine beings, Thales explained them by theorising that the Earth was a large disc which floated on water and that earthquakes occurred when the Earth was rocked by waves.
Thales used geometry to calculate the heights of pyramids and the distance of ships from the shore.
Placing your stick at the end of the shadow of the pyramid, you made by the sun’s rays two triangles, and so proved that the pyramid[height] was to the stick [height] as the shadow of the pyramid to the shadow of the stick.
W. W. Rouse Ball, A Short Account of the History of Mathematics (1893, 1925)
He is the first known individual to use deductive reasoning applied to geometry, by deriving the Thales’ theorem which observed that any triangle which sits along the diameter of a circle will by nature be a right angled triangle.
Thales was one of the seven sages of Greece, ho heptoi sophoi, (οἱ ἑπτὰ σοφοί) alongside Solon of Athens, and Periander of Corinth. These sages were known for pithy sayings including the inscription [attributed to Thales] at the Oracle of Delphi
The Seven Sages of Greece were not only philosophers, scientists and teachers but also involved in political life. Thales political involvement had mainly to do with the involvement of his region, Ionia in the defense of Anatolia [Asia Minor] against the growing power of the Persians. The neighbouring king of Lydia, king Croesus, had conquered many of the coastal cities of the Ionians and he engaged Thales support in his war against the Medes. The war endured for five years, but in the sixth an eclipse of the Sun spontaneously halted a battle in progress (the Battle of Halys). It seems that Thales had predicted this solar eclipse and based on it the Lydians and Medes made peace immediately, swearing a blood oath.
The Medes were vassals of the Persians under Cyrus. Croesus now sided with the Medes against the Persians and marched in the direction of Persia, stopping by the river Halys, then unbridged. The king gave the problem to Thales who got the army across by digging a diversion upstream so as to reduce the flow, making it possible to ford the river. When Croesus was unsuccessful against the Persian armies in Cappadocia, he marched home, and summoned his dependents and allies to send fresh troops to Sardis. The Persian army surrounded the armies of Croesus, trapping them within the walls of Sardis. This time, Thales fame as a counselor was to advise the Milesians not to engage in “fighting together”, with the Lydians against the Persians.
Croesus was defeated before the city of Sardis by Cyrus, and Miletus was subsequently spared because it had taken no action. Cyrus was so impressed by Croesus’ wisdom and his connection with the sages that he spared him and took his advice on various matters. The Ionians were now free and Miletus, received favorable terms from Cyrus including amnesty.
It was Thales wisdom in science, philosophy and politics which led to the rise of the Milesian school of philosophy which was influenced by both Egyptian and Babylonian mathematics and astronomy. It was Anaxagoras [c. 510 – c. 428 BC] of the Milesian school of philosophy who later brought its teaching to Athens, influencing Socrates and Pericles under the Golden Age of Greece.
Although Socrates born two centuries later [c. 470 – 399 BC], is more famously remembered to be the ‘father of western philosophy’, it is Thales earlier wisdom and scientific endeavours that have led to him being credited with fathering western philosophy.