The Ionian Enlightenment was a set of advances in scientific thought, explanations on nature, and discovering the natural and rational causes behind observable phenomena, that took place in archaic Greece beginning in the 6th century BC. This movement began on the Ionian coast of western Anatolia by small numbers of forward-thinking Greeks (see Ionian School and Milesian School) from cities such as Miletus, Samos, and Halicarnassus. They saw the world as something ordered and intelligible, its history following an explicable course and its different parts arranged in a comprehensible system. Most historians agree that Thales, one of the Seven Sages of Greece, started this movement by predicting a solar eclipse that actually occurred, though some believe this feat to be false.
The Greek city of Miletus was the birthplace of Greek philosophy and Western scientific thought. Their culture combined the best of a resurgent Greek civilization with borrowings from Egypt and the Middle East. Internally, the politics of the Milesians were of faction, strife, and bloody revolution; externally, they were neighbored by two powerful empires in the Lydians and Persians. Despite these unfavorable circumstances, the Milesians were commercially indefatigable. With its three harbors and progeny of daughter colonies, Miletus was the "Jewel of Ionia." They traded not only with the Eastern empires, but also with Egypt; they sent out numerous colonies to settle in Thrace and along the coast of the Black Sea; and they had connections with Sybaris in southern Italy. Miletus bred Thales, Anaximander, and Anaximenes; the first three philosophers. Miletus was an essential location for this intellectual revolution to flourish because they had connections with the great civilizations of Egypt, Mesopotamia, and Anatolia which in turn allowed for a vast array of exchange of goods and ideas from across the Mediterranean and three continents.
Up until this point in time (6th century BC) the Greeks, and many empires before them, explained the events of the world as products of supernatural actions of divine agents. This can be seen in the writings of Homer and Hesiod, two famous Greek poets. With the introduction of rational and natural thought the Milesian Presocratic philosophers, as they were termed, attempted to produce an improved and rationalized theology in place of the anthropomorphic divinities of the Olympian pantheon. But their theology had little to do with religion, and they removed most of the traditional functions from the gods, such as thunder was no longer the growling of a minatory Zeus or that Poseidon created storms. This new Presocratic approach gave no direct credence to traditional lore and furthermore these philosophers simply ignored the kinds of explanations that were imbedded in myths and advanced their own accounts on the basis, not of tradition, but of reasons. Their approach refused to allow any supernatural actions to govern natural processes. This rejection of the supernatural did not make the philosophers atheists, rather it made them subordinate divine action to natural law which was known as Physis. These first philosophers offered reasons for their opinions and gave arguments for their views. For the most part, they were concerned not to advance opinions, but to advance reasoned opinions.
This school of thought is made up of the philosophies of three Presocratic philosophers: Thales, Anaximander, and Anaximenes. These philosophers all hailed from the Greek city state of Miletus and are known as the first philosophers. Their philosophy is what started the Ionian Intellectual Revolution.
According to Aristotle, Thales of Miletus was the "Founder of Natural Philosophy." Even though he is recognized as the founder of philosophy much of what we know about him and his philosophy is up to debate because he left no writings for which early students of philosophy could rely on. Known as one of the Seven Sages, which was an exclusive club of poets and statesmen, he was the only one who could claim to be a philosopher and scientist. Thales is credited with being a political adviser, philosopher, scientist, mathematician, and engineer. Throughout his life he is alleged to have traveled and studied throughout the Mediterranean in places such as Egypt, Phoenicia, and Babylon which all influenced his philosophy and theories. Thales allegedly founded geometry, although he may have been taught this in Egypt, and also studied the stars. Thales tried to search for the arkhe, which can be translated to searching for the source for all things. He believed the source for all things (arkhe) was water. This is based on the notion that somehow all things, and more importantly all living things, originate in water and therefore water is the basic starting-point of everything. The apparent stability of the Earth became one phenomenon for which any self-respecting natural philosopher had to have an explanation, for Thales he believed the Earth rested upon water.
Anaximander was a pupil of Thales. Many historians start the beginning of Greek Philosophy and therefore the Ionian Intellectual Revolution with Anaximander since Thales did not leave any written records. Therefore, there is not any reliable information on Thales and the various elements of his thought and practice. Anaximander is responsible for the oldest surviving fragment of Greek philosophical writing. He, as with Thales, offered his own insight into what he believed the arkhe to be which for him was termed "the boundless" (apeiron). This boundless he describes as a principle that is neither water nor any of the other so called elements, but instead some different limitless nature. His principle of "boundless" meant that if mass is anywhere, it is everywhere; at the same time, if empty space is limitless, body too must be limitless. He never explicitly states what this boundless principle is made up of and therefore creates an inevitable question for ancient and modern scholars. Anaximander also theorized about astronomical phenomena such as the distances of the sun, moon, and stars and about the origin and development of living things in the world. He was the first to try and draw the inhabited world on a tablet, and with the help of a traveler from Miletus this tablet was made more accurate. Throughout his life he provides explanations for the existence of the sea, wind, storms, thunder, lightning, and deals a lot with biology.
Anaximenes was a pupil of Anaximander. Of the three philosophers of the Milesian school, Anaximenes is often thought of as the least important simply because he took Anaximander's grand vision of cosmology and identified a mechanism by which it might operate. As with those before him, Anaximenes' arkhe was air (aer). His major philosophical advancement was to posit a clear and definite mechanism by which this aer is transformed into the various more familiar components of the world, thereby tying the world and the arkhe together. Anaximenes theory of change reported that air is the source of everything; there is a set of elements or basic stuffs: (i) fire, (ii) air, (iii) wind, (iv) cloud, (v) water, (vi) earth, (vii) stones, which are ordered by their relative density; and the condensation process is analogous to the action of felting. Anaximenes is usually viewed as the inventor of Material Monism, the theory by which there is only one substance (in this case air) of which all other stuffs are mere modifications or states.
Historians tend to debate on whether the early Greek philosophers were influenced by other ancient empires during the 6th century BC or were the first to think about theory and other sciences such as astrology. Below are some of the possible influencers of the Ionian Intellectual Revolution:
Babylonians were known for their vast knowledge of the skies. Temple Priests kept detailed observations of the skies in order to report and anticipate ominous phenomena. Records of eclipses have been found from around 747 BC. The Babylonians also developed a complex system of mathematics based on the number sixty, which they used to track the motions of the sun and moon. Babylonian archives contained vast stores of mathematical and astronomical data on cuneiform tablets. The eclipse that Thales predicted, which began this movement, may have been done off the basis of Babylonian tablets.
Egyptians were known for their vast knowledge of arithmetic. It is possible that Thales brought back a knowledge of "geometry" from Egypt. The roots of the Greek word mean "earth-measurement", indicating that kind of science he would have encountered there: practical surveying. Egyptians used scribes who had a knowledge of basic arithmetic on which to base practical questions of ordering supplies and the like. They used a simple but highly practical year of 365 days and made simple astronomical observations.