2.1 Thales’s Biography
Thales lived around the mid 620s – mid 540s BC and was born in the city of Miletus. Miletus was an ancient Greek Ionian city on the western coast of Asia Minor (in what is today the Aydin Province of Turkey), near the mouth of the Maeander River.The dates of Thales' life are not known precisely. The time of his life is roughly established by a few dateable events mentioned in the sources and an estimate of his length of life. According to Herodotus, Thales once predicted a solar eclipse which has been determined by modern methods to have been on May 28, 585 BC. Diogenes Laërtius quotes the chronicle of Apollodorus as saying that Thales died at 78 in the 58th Olympiad (548–545), and Sosicrates as reporting that he was 90 at his death.
As mentioned, according to tradition, Thales was born in Miletus, Asia Minor. Diogenes Laertius states that ("according to Herodotus and Douris and Democritus") his parents were Examyes and Cleobuline, Phoenician nobles. Giving another opinion, he ultimately connects Thales' family line back to Phoenician prince Cadmus. Diogenes also reports two other stories, one that he married and had a son, Cybisthus or Cybisthon, or adopted his nephew of the same name. The second is that he never married, telling his mother as a young man that it was too early to marry, and as an older man that it was too late. A much earlier source - Plutarch - tells the following story: Solon who visited Thales asked him the reason which kept him single. Thales answered that he did not like the idea of having to worry about children. Nevertheless, several years later Thales anxious for family adopted his nephew Cybisthus.
Thales involved himself in many activities, taking the role of an innovator. Some say that he left no writings, others that he wrote "On the Solstice" and "On the Equinox". Neither have survived. Diogenes Laërtius quotes letters of Thales to Pherecydes and Solon, offering to review the book of the former on religion, and offering to keep company with the latter on his sojourn from Athens. Thales identifies the Milesians as Athenians
Thales, an engineer by trade, was the first of the Seven Sages, or wise men of Ancient Greece. Thales is known as the first Greek philosopher, mathematician and scientist. He founded the geometry of lines, so is given credit for introducing abstract geometry. He was the founder of the Ionian school of philosophy in Miletus, and the teacher of Anaximander. During Thales' time, Miletus was an important Greek metropolis in Asia Minor, known for scholarship. Several schools were founded in Miletus, attracting scientists, philosophers, architects and geographers
It is possible that Thales has been given credit for discoveries that were not really his. He is known for his theoretical as well as practical understanding of geometry. Thales is acknowledged by a number of sources as the one who defined the constellation Ursa Minor and used it for navigation. Some believe he wrote a book on navigation, but it has never been found.
Two letters and some verses of Thales are quoted by Diogenes Laertius in his Lives of the Philosophers. Much of what we know of Thales as a philosopher comes from Aristotle. Herodotus, who lived approximately sixty years after Thales, also wrote about him, as did Eudemus, the first major historian of mathematics. Proclus, who wrote in about 450 AD, cited Eudemus' History of Geometry, now lost, as his source. Thales is credited with introducing the concepts of logical proof for abstract propositions.
Thales went to Egypt and studied with the priests, where he learned of mathematical innovations and brought this knowledge back to Greece. Thales also did geometrical research and, using triangles, applied his understanding of geometry to calculate the distance from shore of ships at sea. This was particularly important to the Greeks, whether the ships were coming to trade or to do battle. Thales advised Anaximander's student, Pythagoras, to visit Egypt in order to continue his studies in mathematics and philosophy.[1]
2.2 Thales’s Philosophy
Thales’s philosophy in science about . the geometry of lines, so is given credit for introducing abstract geometry.
2.2.1 Ontology
Thales took geometry from the fields to the page by employing two drawing tools, the straightedge for straight lines and the compass for arcs. The Greeks named their paper explorations “geometry” for “earth measure,” in honor of the Egyptians from whom the knowledge came.
Thales is credited with the following five theorems of geometry:
1. A circle is bisected by its diameter
2. Angles at the base of any isosceles triangle are equal.
3. If two straight lines intersect, the opposite angles formed are equal.
4. If one triangle has two angles and one side equal to another triangle, the two triangles are equal in all respects.
5. Any angle inscribed in a semicircle is a right angle. This is known as Thales’ Theorem.
Thales bridged the worlds of myth and reason with his belief that to understand the world, one must know its nature ('physis', hence the modern 'physics'). He believed that all phenomena could be explained in natural terms, contrary to the popular belief at the time that supernatural forces determined almost everything. Thales professed it was "not what we know, but how we know it" (the scientific method). His contributions elevated measurements from practical to philosophical logic.
Water as a first principle
Thales' most famous belief was his cosmological thesis, which held that the world started from water. Aristotle considered this belief roughly equivalent to the later ideas of Anaximenes, who held that everything in the world was composed of air.
The best explanation of Thales' view is the following passage from Aristotle's Metaphysics. The passage contains words from the theory of matter and form that were adopted by science with quite different meanings.
2.2.2 Epistimology
Thales was known for his innovative use of geometry. His understanding was theoretical as well as practical. For example, he said:
Megiston topos: hapanta gar chorei (Μέγιστον τόπος· άπαντα γαρ χωρεί)
”Space is the greatest thing, as it contains all things”
Topos is in Newtonian-style space, since the verb, chorei, has the connotation of yielding before things, or spreading out to make room for them, which is Template:Extension (metaphysics). Within this extension, things have a position. Points, lines, planes and solids related by distances and angles follow from this presumption.
Thales understood similar triangles and right triangles, and what is more, used that knowledge in practical ways. The story is told in DL (loc. cit.) that he measured the height of the pyramids by their shadows at the moment when his own shadow was equal to his height. A right triangle with two equal legs is a 45-degree right triangle, all of which are similar. The length of the pyramid’s shadow measured from the center of the pyramid at that moment must have been equal to its height.
The Greeks often invoked idiosyncratic explanations of natural phenomena by reference to the will of anthropomorphic gods and heroes. Thales, however, aimed to explain natural phenomena via a rational explanation that referenced natural processes themselves. For example, Thales attempted to explain earthquakes by hypothesizing that the Earth floats on water, and that earthquakes occur when the Earth is rocked by waves, rather than assuming that earthquakes were the result of supernatural processes.
Thales, according to Aristotle, asked what was the nature (Greek Arche) of the object so that it would behave in its characteristic way. Physis (φύσις) comes from phyein (φύειν), "to grow", related to our word "be". (G)natura is the way a thing is "born", again with the stamp of what it is in itself.[1]
2.2.3Aksiology
Thales applied his method to objects that changed to become other objects, such as water into earth (he thought). But what about the changing itself? Thales did address the topic, approaching it through lodestone and amber, which, when electrified by rubbing together, also attracts. A concern for magnetism and electrification never left science, being a major part of it today. Even the subatomic particle of electric current is derived from the Greek word ήλεκτρον (ēlektron), which means "amber".
How was the power to move other things without the movers changing to be explained? Thales saw a commonality with the powers of living things to act. The lodestone and the amber must be alive, and if that were so, there could be no difference between the living and the dead. When asked why he didn’t die if there was no difference, he replied “because there is no difference.”
However, Thales was looking for something more general, a universal substance of mind. That also was in the polytheism of the times. Zeus was the very personification of supreme mind, dominating all the subordinate manifestations. From Thales on, however, philosophers had a tendency to depersonify or objectify mind, as though it were the substance of animation per se and not actually a god like the other gods. The end result was a total removal of mind from substanc e, opening the door to a non-divine principle of action. This tradition persisted until Einstein, whose cosmology is quite a different one and does not distinguish between matter and energy.
2.3 Thales Philosophy
The most natural epithets of Thales are "materialist" and "naturalist", which are based on ousia and physis. The Catholic Encyclopedia goes so far as to call him a physiologist, a person who studied physis, despite the fact that we already have physiologists. On the other hand, he would have qualified as an early physicist, as did Aristotle. They studied corpora, "bodies", the medieval descendants of substances.
Most agree that Thales' stamp on thought is the unity of substance, hence Bertrand Russell:
"The view that all matter is one is quite a reputable scientific hypothesis."
"...But it is still a handsome feat to have discovered that a substance remains the same in different states of aggregation."
Russell was only reflecting an established tradition; for example: Nietzsche, in his Philosophy in the Tragic Age of the Greeks, wrote:
"Greek philosophy seems to begin with an absurd notion, with the proposition that water is the primal origin and the womb of all things. Is it really necessary for us to take serious notice of this proposition? It is, and for three reasons. First, because it tells us something about the primal origin of all things; second, because it does so in language devoid of image or fable, and finally, because contained in it, if only embryonically, is the thought, 'all things are one.'"[2]
This sort of materialism, however, should not be confused with deterministic materialism. Thales was only trying to explain the unity observed in the free play of the qualities. The arrival of uncertainty in the modern world made possible a return to Thales; for example, John Elof Boodin writes ("God and Creation"): "We cannot read the universe from the past..."
Boodin defines an "emergent" materialism, in which the objects of sense emerge uncertainly from the substrate. Thales is the innovator of this sort of materialism.
Classical thought, however, had proceeded only a little way along that path. Instead of referring to the person, Zeus, they talked about the great mind:
"Thales", says Cicero, "assures that water is the principle of all things; and that God is that Mind which shaped and created all things from water."
