2 Greek Language, Religion, and Thales
This Chapter is meant to get you started on Greek Philosophy by giving you a good background on the foundations of Greek society, culture, thought, and philosophy, since most of what will be covered in this course can be considered Ancient Greek Philosophy. With that in mind, familiarize yourself with the Greek alphabet and pronunciation since you will inevitably see some in this course. The alphabet is below, and you can find pronunciations of Greek words and letters all over the Internet:
Α α alpha, άλφα [a]
Β β beta, βήτα [b]
Γ γ gamma, γάμμα [ɡ]
Δ δ delta, δέλτα [d]
Ε ε epsilon, έψιλον [e]
Ζ ζ zeta, ζήτα [zd]
Η η eta, ήτα [ɛː]
Θ θ theta, θήτα [tʰ]
Ι ι iota, ιώτα [i]
Κ κ kappa, κάππα [k]
Λ λ lambda, λάμδα [l]
Μ μ mu, μυ [m]
Ν ν nu, νυ [n]
Ξ ξ xi, ξι [ks]
Ο ο omicron, όμικρον [o]
Π π pi, πι [p]
Ρ ρ rho, ρώ [r]
Σ σ/ς sigma, σίγμα [s]
Τ τ tau, ταυ [t]
Υ υ upsilon, ύψιλον [y]
Φ φ phi, φι [pʰ]
Χ χ chi, χι [kʰ]
Ψ ψ psi, ψι [ps]
Ω ω omega, ωμέγα [ɔː]
Ancient Greek Religion2
Ancient Greek religion encompasses the collection of beliefs, rituals, and mythology originating in ancient Greece in the form of both popular public religion and cult practices. These groups varied enough for it to be possible to speak of Greek religions or "cults" in the plural, though most of them shared similarities.
Many ancient Greeks recognized the twelve major (Olympian) gods and goddesses (Zeus, Poseidon, Hera, Demeter, Athena, Ares, Aphrodite, Apollo, Artemis, Hephaestus, Hermes, and either Hestia or Dionysus), although philosophies such as Stoicism and some forms of Platonism used language that seems to assume a single transcendent deity. Different cities often worshiped the same deities, sometimes with epithets that distinguished them and specified their local nature.
The religious practices of the Greeks extended beyond mainland Greece, to the islands and coasts of Ionia in Asia Minor, to Magna Graecia (Sicily and southern Italy), and to scattered Greek colonies in the Western Mediterranean, such as Massalia (Marseille). Greek religion was tempered by Etruscan cult and belief to form much of the later ancient Roman religion.
While there were few concepts universal to all the Greek peoples, there were common beliefs shared by many.
Ancient Greek theology was polytheistic, based on the assumption that there were many gods and goddesses. There was a hierarchy of deities, with Zeus, the king of the gods, having a level of control over all the others, although he was not almighty. Some deities had dominion over certain aspects of nature. For instance, Zeus was the sky-god, sending thunder and lightning, Poseidon ruled over the sea and earthquakes, Hades projected his remarkable power throughout the realms of death and the Underworld, and Helios controlled the sun. Other deities ruled over abstract concepts; for instance Aphrodite controlled love.
While being immortal, the gods were certainly not all-good or even all-powerful. They had to obey fate, known to Greek mythology as the Moirai, which overrode any of their divine powers or wills. For instance, in mythology, it was Odysseus' fate to return home to Ithaca after the Trojan War, and the gods could only lengthen his journey and make it harder for him, but they could not stop him.
The gods acted like humans, and had human vices. They would interact with humans, sometimes even spawning children with them. At times certain gods would be opposed to others, and they would try to outdo each other. In the Iliad, Aphrodite, Ares and Apollo support the Trojan side in the Trojan War, while Hera, Athena and Poseidon support the Greeks (see theomachy).
Some gods were specifically associated with a certain city. Athena was associated with the city of Athens, Apollo with Delphi and Delos, Zeus with Olympia and Aphrodite with Corinth. Other deities were associated with nations outside of Greece; Poseidon was associated with Ethiopia and Troy, and Ares with Thrace.
Identity of names was not a guarantee of a similar cultus; the Greeks themselves were well aware that the Artemis worshipped at Sparta, the virgin huntress, was a very different deity from the Artemis who was a many-breasted fertility goddess at Ephesus. Though the worship of the major deities spread from one locality to another, and though most larger cities boasted temples to several major gods, the identification of different gods with different places remained strong to the end.
The Greeks believed in an underworld where the spirits of the dead went after death. One of the most widespread areas of this underworld was ruled over by Hades, a brother of Zeus, and was known as Hades (originally called 'the place of Hades'). Other well known realms are Tartarus, a place of torment for the damned, and Elysium, a place of pleasantries for the virtuous. In the early Mycenean religion all the dead went to Hades, but the rise of mystery cults in the Archaic age led to the development of places such as Tartarus and Elysium.
A few Greeks, like Achilles, Alcmene, Amphiaraus Ganymede, Ino, Melicertes, Menelaus, Peleus, and a great number of those who fought in the Trojan and Theban wars, were considered to have been physically immortalized and brought to live forever in either Elysium, the Islands of the Blessed, heaven, the ocean, or beneath the ground. Such beliefs are found in the most ancient of Greek sources, such as Homer and Hesiod. This belief remained strong even into the Christian era. For most people at the moment of death there was, however, no hope of anything but continued existence as a disembodied soul.
Some Greeks, such as the philosophers Pythagoras and Plato, also embraced the idea of reincarnation, though this was only accepted by a few. Epicurus taught that the soul was simply atoms which dissolved at death, so there was no existence after death.
Greek religion had an extensive mythology. It consisted largely of stories of the gods and how they interacted with humans. Myths often revolved around heroes and their actions, such as Heracles and his twelve labors, Odysseus and his voyage home, Jason and the quest for the Golden Fleece and Theseus and the Minotaur.
Many species existed in Greek mythology. Chief among these were the gods and humans, though the Titans (who predated the Olympian gods) also frequently appeared in Greek myths. Lesser species included the half-man-half-horse centaurs, the nature based nymphs (tree nymphs were dryads, sea nymphs were Nereids) and the half man, half goat satyrs. Some creatures in Greek mythology were monstrous, such as the one-eyed giant Cyclopes, the sea beast Scylla, whirlpool Charybdis, Gorgons, and the half-man, half-bull Minotaur.
There was not a set Greek cosmogony, or creation myth. Different religious groups believed that the world had been created in different ways. One Greek creation myth was told in Hesiod's Theogony. It stated that at first there was only a primordial deity called Chaos, who gave birth to various other primordial gods, such as Gaia, Tartarus and Eros, who then gave birth to more gods, the Titans, who then gave birth to the first Olympians.
The mythology largely survived and was added to in order to form the later Roman mythology. The Greeks and Romans had been literate societies, and much mythology, although initially shared orally, was written down in the forms of epic poetry (such as the Iliad, the Odyssey and the Argonautica) and plays (such as Euripides' The Bacchae and Aristophanes' The Frogs). The mythology became popular in Christian post-Renaissance Europe, where it was often used as a basis for the works of artists like Botticelli, Michelangelo and Rubens.
Pottery vessel in the shape of Aphrodite isnside a shell; from Attica, Classical Greece, discovered in the Phanagoria cemetery, Taman Peninsula (Bosporan Kingdom, southern Russia), 1st quarter of 4th century BC, Hermitage Museum, Saint Petersburg.
Various religious festivals were held in ancient Greece. Many were specific only to a particular deity or city-state. For example, the festival of Lycaea was celebrated in Arcadia in Greece, which was dedicated to the pastoral god Pan. There were also the Games held each year in different locations, culminating in the Olympic Games, which were held every 4 years. These celebrated Zeus.
One of the most important moral concepts to the Greeks was the fear of committing hubris. Hubris constituted many things, from rape to desecration of a corpse, and was a crime in the city-state of Athens. Although pride and vanity were not considered sins themselves, the Greeks emphasized moderation. Pride only became hubris when it went to extremes, like any other vice. The same was thought of eating and drinking. Anything done to excess was not considered proper. Ancient Greeks placed, for example, importance on athletics and intellect equally. In fact many of their competitions included both. Pride was not evil until it became all-consuming or hurtful to others.
Sacred textsas are other works of classical antiquity, although there were no texts canonized or universally declared as sacred by the ancient Greeks. These are the core texts that were considered inspired and usually include an invocation to the Muses for inspiration at the beginning of the work. Such texts, however, were not considered inspired in the sense that they had to be believed by everyone. Plato even wanted to exclude the myths from his ideal state described in the Republic because of their low moral tone.
While some traditions, such as Mystery cults, did uphold certain texts as canonic within their own cult praxis, such texts were respected but not necessarily accepted as canonic outside their circle. In this field, of particular importance are certain texts referring to Orphic cults: multiple copies, ranging from 450 BC to 250 AD, have been found in various locations of the Greek world. Even the words of the oracles never turned into a sacred text. Other texts were specially composed for religious events, and some have survived within the lyric tradition; although they had a cult function, they were bound to performance and never developed into a common, standard prayer form comparable to the Christian Pater Noster. An exception to this rule were the already named Orphic and Mystery rituals, which, in this, set themselves aside from the rest of the Greek religious system. Finally, some texts called hieroi logoi (sacred texts) by the ancient sources, originated from outside the Greek world, or were supposedly adopted in remote times, representing yet more different traditions within the Greek belief system.
The lack of a unified priestly class meant that a unified, canonic form of the religious texts or practices never existed: just as there was no unified, common sacred text for the Greek belief system, there was no standardization of practices. Instead, religious practices were organized on local levels, with priests normally being magistrates for the city or village, or gaining authority from one of the many sanctuaries. Some priestly functions, like the care for a particular local festival, could be given by tradition to a certain family.
Greek ceremonies and rituals were mainly performed at altars. These were typically devoted to one or a few gods, and supported a statue of the particular deity. Votive deposits would be left at the altar, such as food, drinks, as well as precious objects. Sometimes animal sacrifices would be performed here, with most of the flesh eaten, and the offal burnt as an offering to the gods. Libations, often of wine, would be offered to the gods as well, not only at shrines, but also in everyday life, such as during a symposium.
One ceremony was pharmakos, a ritual involving expelling a symbolic scapegoat such as a slave or an animal, from a city or village in a time of hardship. It was hoped that by casting out the ritual scapegoat, the hardship would go with it.
Worship in Greece typically consisted of sacrificing domestic animals at the altar with hymn and prayer. Parts of the animal were then burned for the gods; the worshippers would eat the rest. The evidence of the existence of such practices is clear in some ancient Greek literature, especially in Homer's epics. Throughout the poems, the use of the ritual is apparent at banquets where meat is served, in times of danger or before some important endeavor to gain the favor of the gods. For example, in Homer's the Odyssey Eumaeus sacrifices a pig with prayer for his unrecognizable master Odysseus. In Homer's the Iliad, which may describe Greek civilization centuries earlier, every banquet of the princes begins with a sacrifice and prayer.
These sacrificial practices, described in these pre-Homeric eras, share commonalities to the 8th century forms of sacrificial rituals. Furthermore, throughout the poem, special banquets are held whenever gods indicated their presence by some sign or success in war. Before setting out for Troy, this type of animal sacrifice is offered. Odysseus offers Zeus a sacrificial ram in vain. The occasions of sacrifice in Homer's epic poems may shed some light onto the view of the gods as members of society, rather than as external entities, indicating social ties. Sacrificial rituals played a major role in forming the relationship between humans and the divine.
Rites of passage
One rite of passage was the amphidromia, celebrated on the fifth or seventh day after the birth of a child. Childbirth was extremely significant to Athenians, especially if the baby was a boy.
Those who were not satisfied by the public cult of the gods could turn to various mystery religions which operated as cults into which members had to be initiated in order to learn their secrets.
Here, they could find religious consolations that traditional religion could not provide: a chance at mystical awakening, a systematic religious doctrine, a map to the afterlife, a communal worship, and a band of spiritual fellowship.
Some of these mysteries, like the mysteries of Eleusis and Samothrace, were ancient and local. Others were spread from place to place, like the mysteries of Dionysus. During the Hellenistic period and the Roman Empire, exotic mystery religions became widespread, not only in Greece, but all across the empire. Some of these were new creations, such as Mithras, while others had been practiced for hundreds of years before, like the Egyptian mysteries of Osiris.
Mainstream Greek religion appears to have developed out of Proto-Indo-European religion and most immediately to have evolved from the earlier Mycenaean religion of the Mycenaean civilization of Bronze Age Greece. The Mycenaeans, according to archaeological discoveries, seemed to treat Poseidon as their chief deity. Greek religious concepts may also have absorbed the beliefs and practices of earlier, nearby cultures, such as Minoan religion. Herodotus, writing in the 5th century BCE, traced many Greek religious practices to Egypt.
The mainstream religion of the Greeks did not go unchallenged within Greece. Several notable philosophers criticised a belief in the gods. The earliest of these was Xenophanes, who chastised the human vices of the gods as well as their anthropomorphic depiction. Plato did not believe in many deities, but instead believed that there was one supreme god, whom he called the Form of the good, and which he believed was the emanation of perfection in the universe. Plato's disciple, Aristotle, also disagreed that polytheistic deities existed, because he could not find enough empirical evidence for it. He believed in a Prime Mover, which had set creation going, but was not connected to or interested in the universe.
When the Roman Republic conquered Greece in 146 BC, it took much of Greek religion (along with many other aspects of Greek culture such as literary and architectural styles) and incorporated it into its own. The Greek gods were equated with the ancient Roman deities; Zeus with Jupiter, Hera with Juno, Poseidon with Neptune, Aphrodite with Venus, Ares with Mars, Artemis with Diana, Athena with Minerva, Hermes with Mercury, Hephaestus with Vulcan, Hestia with Vesta, Demeter with Ceres, Hades with Pluto, Tyche with Fortuna, and Pan with Faunus. Some of the gods, such as Apollo and Bacchus, had earlier been adopted by the Romans. There were also many deities that existed in the Roman religion before its interaction with Greece that weren't associated with a Greek deity, including Janus and Quirinus.
Greek religion and philosophy have experienced a number of revivals, most notably in the arts, humanities and spirituality of the Renaissance. More recently, a revival has begun with the contemporary Hellenism, as it is often called (a term first used by the last pagan Roman emperor Julian). In Greece, the term used is Hellene ethnic religion (Greek: Ελληνική Εθνική Θρησκεία).
Modern Hellenism reflects Neoplatonic/Platonic speculation (which is represented in Porphyry, Libanius, Proclus, and Julian), as well as classical cult practice. However, there are many fewer followers than Greek Orthodox Christianity. According to estimates reported by the U.S. State Department, there are perhaps as many as 2,000 followers of the ancient Greek religion out of a total Greek population of 11 million; however, Hellenism's leaders place that figure at 100,000 followers
Thales, the First Philosopher3
Thales of Miletus (/ˈθeɪliːz/; Greek: Θαλῆς (ὁ Μῑλήσιος), Thalēs; c. 624 – c. 546 BC) was a pre-Socratic Greek/Phonecian philosopher, mathematician and astronomer from Miletus in Asia Minor, current day Milet in Turkey and one of the Seven Sages of Greece. Many, most notably Aristotle, regard him as the first philosopher in the Greek tradition, and he is otherwise historically recognised as the first individual in Western civilisation known to have entertained and engaged in scientific thought, (i.e. empiricism).
Thales is recognised as having made a break from understanding the world and universe by mythological explanations to instead find explanations for the existence of natural things and phenomena by theories and hypothesis, ergo science. Almost all of the other Pre-Socratic philosophers proceed after him to provide explanations of natural things by way of there being a unity of everything because of the existence of a single ultimate substance, instead of explanation given by mythology. Aristotle reported Thales's hypothesis that the originating principle of nature and the nature of matter was a single material substance: water.
In mathematics, Thales used geometry to calculate the heights of pyramids and the distance of ships from the shore. He is the first known individual to use deductive reasoning applied to geometry, by deriving four corollaries to Thales' theorem. He is the first known individual to whom a mathematical discovery has been attributed.
The current historical consensus is that Thales was born in the city of Miletus around the mid 620s BC from Phoenician parents, although some historians say he was a Phoenician who emigrated to Miletus with his parents.
The ancient source, Apollodorus of Athens, writing during the 2nd century BCE, thought Thales was born about the year 625 BCE.
The dates of Thales' life are not exactly known but are roughly established by a few datable events mentioned in the sources. According to Herodotus (and as determined by modern methods), Thales predicted the solar eclipse of May 28, 585 BC. Diogenes Laërtius quotes the chronicle of Apollodorus of Athens as saying that Thales died at the age of 78 during the 58th Olympiad (548–545 BC) and attributes his death to heat stroke while watching the games.
Diogenes Laërtius states that "according to Herodotus and Douris and Democritus", Thales' parents were Examyes and Cleobuline, both wealthy and distinguished phoenicians, and then traces the family line back to Cadmus, a mythological Phoenician prince of Tyre. Diogenes then delivers conflicting reports: one that Thales married and either fathered a son (Cybisthus or Cybisthon) or adopted his nephew of the same name; the second 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. Plutarch had earlier told this version: Solon visited Thales and asked him why he remained single; Thales answered that he did not like the idea of having to worry about children. Nevertheless, several years later, anxious for family, he adopted his nephew Cybisthus.
Thales involved himself in many activities, taking the role of an innovator. Some say that he left no writings, others say that he wrote On the Solstice and On the Equinox. (No writing attributed to him has survived.) Diogenes Laërtius quotes two letters from Thales: one to Pherecydes of Syros offering to review his book on religion, and one to Solon, offering to keep him company on his sojourn from Athens. Thales identifies the Milesians as Athenian colonists.
Thales' principal occupation was engineering.
He was aware of the existence of the lodestone, and was the first to be connected to knowledge of this in history. According to Aristotle, Thales thought lodestones had souls, because of the fact of iron being attracted to them (which occurs through forces of magnetism). According to Hieronymus, historically quoted by Diogenes Laertius, Thales found out the height of pyramids by comparison between the shadows cast by a person and the pyramids.
Several anecdotes suggest Thales was not solely a philosopher, but also involved in business.
A story, with different versions, recounts how Thales achieved riches from an olive harvest by prediction of the weather.
In one version, he bought all the olive presses in Miletus after predicting the weather and a good harvest for a particular year. Another version of the story has Aristotle explain Thales had reserved presses ahead of time at a discount only to rent them out at a high price when demand peaked, following his predictions of a particularly good harvest. Aristotle explains that Thales' objective in doing this was not to enrich himself but to prove to his fellow Milesians that philosophy could be useful, contrary to what they thought, or alternatively, Thales had made his foray into enterprise because of a personal challenge put to him by an individual who had asked why if Thales were intelligent, by way of being a reputed philosopher, he had yet to attain wealth. This first version of the story would constitute the first historically known creation and use of futures, whereas the second version would be the first historically known of creation and use of options.
Diogenes Laërtius tells us that the Seven Sages were created in the archonship of Damasius at Athens about 582 BC and that Thales was the first sage. The same story, however, asserts that Thales emigrated to Miletus. There is also a report that he did not become a student of nature until after his political career. Much as we would like to have a date on the seven sages, we must reject these stories and the tempting date if we are to believe that Thales was a native of Miletus, predicted the eclipse, and was with Croesus in the campaign against Cyrus.
Thales received instruction from an Egyptian priest. It was fairly certain that he came from a wealthy, established family, in a class which customarily provided higher education for their children. Moreover, the ordinary citizen, unless he was a seafaring man or a merchant, could not afford the grand tour in Egypt, and did not consort with noble lawmakers such as Solon.
In Diogenes Laërtius' Lives of Eminent Philosophers Chapter 1.39, Laërtius relates the several stories of an expensive object that is to go to the most wise. In one version (that Laërtius credits to Callimachus in his Iambics) Bathycles of Arcadia states in his will that an expensive bowl "'should be given to him who had done most good by his wisdom.' So it was given to Thales, went the round of all the sages, and came back to Thales again. And he sent it to Apollo at Didyma, with this dedication...'Thales the Milesian, son of Examyas [dedicates this] to Delphinian Apollo after twice winning the prize from all the Greeks.'"
See also: "The Astrologer who Fell into a Well"Thales described the position of Ursa Minor, and thought the constellation might be useful as a guide for navigation at sea. He calculated the duration of the year and the timings of the equinoxes and solstices. He is additionally attributed with the first observation of the Hyades and with calculating the position of the Pleiades. Plutarch indicates that in his day (c. AD 100) there was an extant work, the Astronomy, composed in verse and attributed to Thales.
The Greeks often invoked idiosyncratic explanations of natural phenomena with reference to the will of anthropomorphic gods and heroes. Instead, Thales aimed to explain natural phenomena via rational hypotheses that referenced natural processes themselves. For example, rather than assuming that earthquakes were the result of supernatural whims Thales explained them by hypothesizing that the Earth floats on water and that earthquakes occur when the Earth is rocked by waves.
Thales was a hylozoist (one who thinks that matter is alive, i.e. containing soul(s)). Aristotle wrote (De Anima 411 a7-8) of Thales: ...Thales thought all things are full of gods. Aristotle posits the origin of Thales thought on matter generally containing souls, to Thales thinking initially on the fact of, because magnets move iron, the presence of movement of matter indicated this matter contained life.
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.
Aristotle characterizes most of the philosophers "at first" (πρῶτον) as thinking that the "principles in the form of matter were the only principles of all things", where "principle" is arche, "matter" is hyle ("wood" or "matter", "material") and "form" is eidos.
Arche is translated as "principle", but the two words do not have precisely the same meaning. A principle of something is merely prior (related to pro-) to it either chronologically or logically. An arche (from ἄρχειν, "to rule") dominates an object in some way. If the arche is taken to be an origin, then specific causality is implied; that is, B is supposed to be characteristically B just because it comes from A, which dominates it.
The archai that Aristotle had in mind in his well-known passage on the first Greek scientists are not necessarily chronologically prior to their objects, but are constituents of it. For example, in pluralism objects are composed of earth, air, fire and water, but those elements do not disappear with the production of the object. They remain as archai within it, as do the atoms of the atomists.
What Aristotle is really saying is that the first philosophers were trying to define the substance(s) of which all material objects are composed. As a matter of fact, that is exactly what modern scientists are attempting to accomplish in nuclear physics, which is a second reason why Thales is described as the first western scientist.
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· ἄπαντα γὰρ χωρεῖ.)
"The greatest is space, for it holds 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 extension. 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.
This story indicates that he was familiar with the Egyptian seked, or seqed - the ratio of the run to the rise of a slope (cotangent). The seked is at the base of problems 56, 57, 58, 59 and 60 of the Rhind papyrus – an ancient Egyptian mathematical document.
In present-day trigonometry, cotangents require the same units for run and rise (base and perpendicular), but the papyrus uses cubits for rise and palms for run, resulting in different (but still characteristic) numbers. Since there were 7 palms in a cubit, the seked was 7 times the cotangent.
To use an example often quoted in modern reference works, suppose the base of a pyramid is 140 cubits and the angle of rise 5.25 seked. The Egyptians expressed their fractions as the sum of fractions, but the decimals are sufficient for the example. What is the rise in cubits? The run is 70 cubits, 490 palms. X, the rise, is 490 divided by 5.25 or 93 1⁄3 cubits. These figures sufficed for the Egyptians and Thales. We would go on to calculate the cotangent as 70 divided by 93 1⁄3 to get 3/4 or .75 and looking that up in a table of cotangents find that the angle of rise is a few minutes over 53 degrees.
Whether the ability to use the seked, which preceded Thales by about 1000 years, means that he was the first to define trigonometry is a matter of opinion. More practically Thales used the same method to measure the distances of ships at sea, said Eudemus as reported by Proclus ("in Euclidem"). According to Kirk & Raven (reference cited below), all you need for this feat is three straight sticks pinned at one end and knowledge of your altitude. One stick goes vertically into the ground. A second is made level. With the third you sight the ship and calculate the seked from the height of the stick and its distance from the point of insertion to the line of sight.
The seked is a measure of the angle. Knowledge of two angles (the seked and a right angle) and an enclosed leg (the altitude) allows you to determine by similar triangles the second leg, which is the distance. Thales probably had his own equipment rigged and recorded his own sekeds, but that is only a guess.
Cosmology: water as a first principle
Thales' most famous philosophical position was his cosmological thesis, which comes down to us through a passage from Aristotle's Metaphysics. In the work Aristotle unequivocally reported Thales’ hypothesis about the nature of all matter – that the originating principle of nature was a single material substance: water. Aristotle then proceeded to proffer a number of conjectures based on his own observations to lend some credence to why Thales may have advanced this idea (though Aristotle didn’t hold it himself).
Aristotle laid out his own thinking about matter and form which may shed some light on the ideas of Thales, in Metaphysics 983 b6 8–11, 17–21. (The passage contains words that were later adopted by science with quite different meanings.)
"That from which is everything that exists and from which it first becomes and into which it is rendered at last, its substance remaining under it, but transforming in qualities, that they say is the element and principle of things that are. …For it is necessary that there be some nature (φύσις), either one or more than one, from which become the other things of the object being saved... Thales the founder of this type of philosophy says that it is water."
In this quote we see Aristotle's depiction of the problem of change and the definition of substance. He asked if an object changes, is it the same or different? In either case how can there be a change from one to the other? The answer is that the substance "is saved", but acquires or loses different qualities (πάθη, the things you "experience").
Aristotle conjectured that Thales reached his conclusion by contemplating that the "nourishment of all things is moist and that even the hot is created from the wet and lives by it." While Aristotle's conjecture on why Thales held water as the originating principle of matter is his own thinking, his statement that Thales held it as water is generally accepted as genuinely originating with Thales and he is seen as an incipient matter-and-formist.
Thales thought the Earth must be a flat disk which is floating in an expanse of water.
Heraclitus Homericus states that Thales drew his conclusion from seeing moist substance turn into air, slime and earth. It seems likely that Thales viewed the Earth as solidifying from the water on which it floated and the oceans that surround it.
Writing centuries later, Diogenes Laërtius also states that Thales taught "Water constituted (ὑπεστήσατο, 'stood under') the principle of all things."
Aristotle considered Thales’ position to be roughly the equivalent to the later ideas of Anaximenes, who held that everything was composed of air.
The 1870 book Dictionary of Greek and Roman Biography and Mythology noted
Thales dogma that water is the origin of things, that is, that it is that out of which every thing arises, and into which every thing resolves itself, Thales may have followed Orphic cosmogonies, while, unlike them, he sought to establish the truth of the assertion. Hence, Aristotle, immediately after he has called him the originator of philosophy brings forward the reasons which Thales was believed to have adduced in confirmation of that assertion; for that no written development of it, or indeed any book by Thales, was extant, is proved by the expressions which Aristotle uses when he brings forward the doctrines and proofs of the Milesian. (p. 1016)
Later scholastic thinkers would maintain that in his choice of water Thales was influenced by Babylonian or Chaldean religion, that held that a god had begun creation by acting upon the pre-existing water. Historian Abraham Feldman holds this does not stand up under closer examination. In Babylonian religion the water is lifeless and sterile until a god acts upon it, but for Thales water itself was divine and creative. He maintained that "All things are full of gods", and to understand the nature of things was to discover the secrets of the deities, and through this knowledge open the possibility that one could be greater than the grandest Olympian.
Feldman points out that while other thinkers recognized the wetness of the world "none of them was inspired to conclude that everything was ultimately aquatic." He further points out that Thales was "a wealthy citizen of the fabulously rich Oriental port of Miletus...a dealer in the staples of antiquity, wine and oil...He certainly handled the shell-fish of the Phoenicians that secreted the dye of imperial purple." Feldman recalls the stories of Thales measuring the distance of boats in the harbor, creating mechanical improvements for ship navigation, giving an explanation for the flooding of the Nile (vital to Egyptian agriculture and Greek trade), and changing the course of the river Halys so an army could ford it. Rather than seeing water as a barrier Thales contemplated the Ionian yearly religious gathering for athletic ritual (held on the promontory of Mycale and believed to be ordained by the ancestral kindred of Poseidon, the god of the sea). He called for the Ionian mercantile states participating in this ritual to convert it into a democratic federation under the protection of Poseidon that would hold off the forces of pastoral Persia. Feldman concludes that Thales saw "that water was a revolutionary leveler and the elemental factor determining the subsistence and business of the world" and "the common channel of states."This combined with his contemporary's idea of "spontaneous generation" allow us to see how Thales could hold that water could be divine and creative.
Feldman points to the lasting association of the theory that "all whatness is wetness" with Thales himself, pointing out that Diogenes Laërtius speaks of a poem, probably a satire, where Thales is snatched to heaven by the sun, "Perhaps it was an elaborate paronomasia based on the fact that thal was the Phoenician word for dew."
Beliefs in divinity
Thales applied his method to objects that changed to become other objects, such as water into earth (or so 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. It is noteworthy that the first particle known to carry electric charge, the electron, is named for the Greek word for amber, ἤλεκτρον (ēlektron).
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."
Aristotle defined the soul as the principle of life, that which imbues the matter and makes it live, giving it the animation, or power to act. The idea did not originate with him, as the Greeks in general believed in the distinction between mind and matter, which was ultimately to lead to a distinction not only between body and soul but also between matter and energy.
If things were alive, they must have souls. This belief was no innovation, as the ordinary ancient populations of the Mediterranean did believe that natural actions were caused by divinities. Accordingly, the sources say that Thales believed that "all things were full of gods." In their zeal to make him the first in everything some said he was the first to hold the belief, which must have been widely known to be false.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 substance, opening the door to a non-divine principle of action.
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."
The universal mind appears as a Roman belief in Virgil as well:
"In the beginning, SPIRIT within (spiritus intus) strengthens Heaven and Earth,
The watery fields, and the lucid globe of Luna, and then --
Titan stars; and mind (mens) infused through the limbs
Agitates the whole mass, and mixes itself with GREAT MATTER (magno corpore)"
According to Henry Fielding, Diogenes Laërtius affirmed that Thales posed "the independent pre-existence of God from all eternity, stating "that God was the oldest of all beings, for he existed without a previous cause even in the way of generation; that the world was the most beautiful of all things; for it was created by God."
Thales (who died around 30 years before the time of Pythagoras and 300 years before Euclid, Eudoxus of Cnidus, and Eudemus of Rhodes) is often hailed as "the first Greek mathematician". While some historians, such as Colin R. Fletcher, point out that there could have been a predecessor to Thales who would've been named in Eudemus' lost book History of Geometry it is admitted that without the work "the question becomes mere speculation." Fletcher holds that as there is no viable predecessor to the title of first Greek mathematician, the only question is whether Thales qualifies as a practitioner in that field; he holds that "Thales had at his command the techniques of observation, experimentation, superposition and deduction…he has proved himself mathematician."
The evidence for the primacy of Thales comes to us from a book by Proclus who wrote a thousand years after Thales but is believed to have had a copy of Eudemus' book. Proclus wrote "Thales was the first to go to Egypt and bring back to Greece this study." He goes on to tell us that in addition to applying the knowledge he gained in Egypt "He himself discovered many propositions and disclosed the underlying principles of many others to his successors, in some case his method being more general, in others more empirical."
Other quotes from Proclus list more of Thales' mathematical achievements:
"They say that Thales was the first to demonstrate that the circle is bisected by the diameter, the cause of the bisection being the unimpeded passage of the straight line through the centre."
"[Thales] is said to have been the first to have known and to have enunciated [the theorem] that the angles at the base of any isosceles triangle are equal, though in the more archaic manner he described the equal angles as similar."
"This theorem, that when two straight lines cut one another, the vertical and opposite angles are equal, was first discovered, as Eudemus says, by Thales, though the scientific demonstration was improved by the writer of Elements."
"Eudemus in his History of Geometry attributes this theorem [the equality of triangles having two angles and one side equal] to Thales. For he says that the method by which Thales showed how to find the distance of ships at sea necessarily involves this method."
"Pamphila says that, having learnt geometry from the Egyptians, he [Thales] was the first to inscribe in a circle a right-angled triangle, whereupon he sacrificed an ox."
In addition to Proclus, Hieronymus of Rhodes also cites Thales as the first Greek mathematician. Hieronymus held that Thales was able to measure the height of the pyramids by using a theorem of geometry now known as the intercept theorem, (after gathering data by using his walking-stick and comparing its shadow to those cast by the pyramids). We receive variations of Hieronymus' story through Diogenes Laërtius, Pliny the Elder, and Plutarch.  Due to the variations among testimonies, such as the "story of the sacrifice of an ox on the occasion of the discovery that the angle on a diameter of a circle is a right angle" in the version told by Diogenes Laërtius being accredited to Pythagoras rather than Thales, some historians (such as D. R. Dicks) question whether such anecdotes have any historical worth whatsoever.
In the long sojourn of philosophy, there has existed hardly a philosopher or historian of philosophy who did not mention Thales and try to characterize him in some way. He is generally recognized as having brought something new to human thought. Mathematics, astronomy, and medicine already existed. Thales added something to these different collections of knowledge to produce a universality, which, as far as writing tells us, was not in tradition before, but resulted in a new field.
Ever since, interested persons have been asking what that new something is. Answers fall into (at least) two categories, the theory and the method. Once an answer has been arrived at, the next logical step is to ask how Thales compares to other philosophers, which leads to his classification (rightly or wrongly).
The most natural epithets of Thales are "materialist" and "naturalist", which are based on ousia and physis. The Catholic Encyclopedia notes that Aristotle called him a physiologist, with the meaning "student of nature." 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.'"
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.
Rise of theoretical inquiry
In the West, Thales represents a new kind of inquiring community as well. Edmund Husserlattempts to capture the new movement as follows. Philosophical man is a "new cultural configuration" based in stepping back from "pregiven tradition" and taking up a rational "inquiry into what is true in itself;" that is, an ideal of truth. It begins with isolated individuals such as Thales, but they are supported and cooperated with as time goes on. Finally the ideal transforms the norms of society, leaping across national borders.
The term "Pre-Socratic" derives ultimately from the philosopher Aristotle, who distinguished the early philosophers as concerning themselves with substance.
Diogenes Laërtius on the other hand took a strictly geographic and ethnic approach. Philosophers were either Ionian or Italian. He used "Ionian" in a broader sense, including also the Athenian academics, who were not Pre-Socratics. From a philosophic point of view, any grouping at all would have been just as effective. There is no basis for an Ionian or Italian unity. Some scholars, however, concede to Diogenes' scheme as far as referring to an "Ionian" school. There was no such school in any sense.
The most popular approach refers to a Milesian school, which is more justifiable socially and philosophically. They sought for the substance of phenomena and may have studied with each other. Some ancient writers qualify them as Milesioi, "of Miletus."
Influence on others
Thales had a profound influence on other Greek thinkers and therefore on Western history. Some believe Anaximander was a pupil of Thales. Early sources report that one of Anaximander's more famous pupils, Pythagoras, visited Thales as a young man, and that Thales advised him to travel to Egypt to further his philosophical and mathematical studies.
Many philosophers followed Thales' lead in searching for explanations in nature rather than in the supernatural; others returned to supernatural explanations, but couched them in the language of philosophy rather than of myth or of religion.and furthermore it does not differentiate between nature and culture. The way a logos thinker would present a world view is radically different from the way of the mythical thinker. In its concrete form, logos is a way of thinking not only about individualism, but also the abstract. Furthermore, it focuses on sensible and continuous argumentation. This lays the foundation of philosophy and its way of explaining the world in terms of abstract argumentation, and not in the way of gods and mythical stories.