Prof. Diego ManettiFilosofia
Presocratics
Our western philosophical tradition began in ancient Greece in the 6th century BCE. The first philosophers are called "Presocratics" which designates that they came before Socrates.
The Presocratic's most distinguishing feature is emphasis on questions of physics; indeed, Aristotle refers to them as "Investigators of Nature". Their scientific interests included mathematics, astronomy, and biology. As the first philosophers, though, they emphasized the rational unity of things, and rejected mythological explanations of the world. Only fragments of the original writings of the presocratics survive, in some cases merely a single sentence. The knowledge we have of them derives from accounts of early philosophers, such as Aristotle's Physics and Metaphysics, The Opinions of the Physicists by Aristotle's pupil Theophratus.
The first group of Presocratic philosophers were from Ionia. The Ionian philosophers sought the material principle (archê) of things, and the mode of their origin and disappearance.
Thales of Miletus
Thales was born in Miletus in Greek Ionia in the mid 620s BCE and died in about 546 BCE. Aristotle, the major source for Thales's philosophy and science, identified Thales as the founder of the school of natural philosophy. Thales was interested in almost everything, investigating almost all areas of knowledge, philosophy, history, science, mathematics, engineering, geography, and politics. He proposed theories to explain many of the events of nature and the problems of Astronomy: provided a number of explanations of cosmological events which traditionally involved supernatural entities.
He founded the Milesian school of natural philosophy, developed the scientific method, and initiated the first western enlightenment.
The Writings of Thales
Doubts have always existed about whether Thales wrote anything, but a number of ancient reports credit him with writings.
It is difficult to believe that Thales would not have written down the information he had gathered in his travels, particularly the geometry he investigated in Egypt and his measuring of the height of the pyramid, his hypotheses about nature, and the cause of change.
Thales says Water is the Primary Principle
Aristotle described Thales as the founder of natural philosophy (Metaph. 983 b21-22). He recorded: 'Thales says that it is water'. 'it' is the nature, the archê, the originating principle. For Thales, this nature was a single material substance, water.
Thales and Mythology
Thales was esteemed in his times as an original thinker, who broke with tradition and existing mythologies. He supplanted myth in his explanations of the behaviour of natural phenomena.
Thales did not derive his thesis from either Greek or non-Greek mythological traditions. He would have been familiar with Homer's acknowledgements of divine progenitors but he never attributed organization or control of the cosmos to the gods. Aristotle recognized the similarity between Thales's doctrine about water and the ancient legend which associates water with Oceanus and Tethys, but he reported that Thales declared water to be the nature of all things. Aristotle pointed to a similarity to traditional beliefs, not a dependency upon them and acknowledged Thales as the founder of natural philosophy.
Thales's Primary Principle
The problem of the nature of matter, and its transformation into the myriad things of which the universe is made, engaged the natural philosophers, commencing with Thales.
Aristotle reported Thales's pronouncement about the primary principle: 'Thales says that it [the nature of things] is water' (Metaph. 983 b20). It was Aristotle's opinion that Thales may have observed, 'that the nurture of all creatures is moist, and that warmth itself is generated from moisture and lives by it; and that from which all things come to be is their first principle'. (…) 'Besides this, another reason for the supposition would be that the semina of all things have a moist nature… That from which all things come to be is their first principle'.
Water exhibits sensible changes more obviously than any of the other so-called elements, and can readily be observed in the three states of liquid, vapour and ice.
To Thales water held the potentialities for the nourishment and generation of the entire cosmos.
The Earth Floats on Water
In De Caelo Aristotle wrote: 'This [opinion that the earth rests on water] is the most ancient explanation which has come down to us, and is attributed to Thales of Miletus. He explained his theory by adding the analogy that the earth is at rest because it is of the nature of wood and similar substances which have the capacity to float on water, although not on air. In Metaphysics (983 b21) Aristotle stated, quite unequivocally: 'Thales . . . declared that the earth rests on water'.
Thales may have reasoned that as a modification of water, earth must be the lighter substance, and floating islands do exist.
The Milesian School
Thales was the founder of a new school of philosophy. His two fellow Milesians who also engaged in the new questioning approach to the understanding of the universe, were Anaximander, his disciple, and Anaximenes, who was the disciple of Anaximander.
Through their association they comprised the Milesian School: They all worked on similar problems, the nature of matter and the nature of change, but they each proposed a different material as the primary principle, which indicates that there was no necessity to follow the master's teachings. Thales was held in high regard for his wisdom, being acclaimed as the most eminent of the Wise Men of Ancient Greece, but he was not regarded as a god, as Pythagoras was. Anaximander and Anaximenes were free to pursue their own ideas and to express them in writing. This surely suggests that they engaged in critical discussion of the theories of each other. There was a unique relationship between the three Milesians and it is highly probable that the critical method developed in the Milesian School under the leadership of Thales.
The Heritage of Thales
Thales is the first person about whom we know to propose explanations of natural phenomena which were materialistic rather than mythological or theological. His theories were new, bold, exciting, comprehensible, and possible of explanation.
Because he gave no role to mythical beings, Thales's theories could be refuted. Thales's hypotheses were rational and scientific.
The most outstanding aspects of Thales's heritage are: the search for knowledge for its own sake; the development of the scientific method; his curiosity and conjectural approach to the questions of natural phenomena.
In the sixth century BCE Thales asked the question, 'What is the basic material of the cosmos?' The answer is yet to be discovered.
Anaximander
Anaximander (c. 610-546 BCE) was the author of the first surviving lines of western philosophy.
He speculated and argued about 'the Boundless' as the origin of all that is. He also worked on the fields of what we now call geography and biology. Moreover, Anaximander was the first speculative astronomer.
Life and sources
The history of written Greek philosophy starts with Anaximander of Miletus in Asia Minor, a fellow-citizen of Thales. He was the first who dared to write a treatise in prose, which has been called traditionally On Nature. This book has been lost, although it probably was available in the library of the Lyceum at the times of Aristotle.
We also know very little of Anaximander's life. He seems to have been a much-traveled man, which is not astonishing, as the Milesians were known to be audacious sailors. Most of the information on Anaximander comes from Aristotle and his pupil Theophrastus, who wrote a book on the history of philosophy.
The 'Boundless' as principle
The first Greek philosophers were looking for the 'origin' or 'principle' (the Greek word 'archê' has both meanings) of all things. Anaximander is said to have identified it with 'the Boundless' or 'the Unlimited' (Greek: 'apeiron', i.e. 'that which has no boundaries').
Already in ancient times, it is complained that Anaximander did not explain what he meant by 'the Boundless'. More recently, authors have disputed whether the Boundless should be interpreted as spatially or temporarily without limits, or perhaps as that which has no qualifications, or as that which is inexhaustible.
However, Greek philosophy, by making the Boundless into the principle of all things, has started on a high level of abstraction.
The arguments regarding the Boundless
It seems that Anaximander not only put forward the thesis that the Boundless is the principle, but also tried to argue for it. We might say that he was the first who made use of philosophical arguments. This is what makes him the first philosopher.
The Boundless has no origin
Anaximander argued that the Boundless has no origin, because it is itself the origin. We would say that it looks more like a string of associations and word-plays than like a formal argument. It runs as follows: "Everything has an origin or is an origin. The Boundless has no origin. For then it would have a limit. Moreover, it is both unborn and immortal, being a kind of origin. For that which has become has also, necessarily, an end, and there is a termination to every process of destruction" (Aristotle, Physics).
The Greeks were familiar with the idea of the immortal Homeric gods. Anaximander added two distinctive features to the concept of divinity: his Boundless is an impersonal something (or 'nature', the Greek word is 'physis'), and it is not only immortal but also unborn.
The origin must be boundless
Several sources give another argument which is somehow the other way round and answers the question of why the origin should be boundless. In Aristotle's version, it runs like this: "(Thebelief that there is something Boundless stems from) the idea that only then genesis and decay will never stop, when that from which is taken what has been generated, is boundless" (Physics).
In this argument, the Boundless seems to be associated with an inexhaustible source. Obviously, it is taken for granted that "genesis and decay will never stop", and the Boundless has to guarantee the ongoing of the process, like an ever-floating fountain.
The fragment
The only existing fragment of Anaximander's book is surrounded by all kinds of questions. The ancient Greeks did not use quotation marks, so that we cannot be sure where Simplicius, who has handed down the text to us, is still paraphrasing Anaximander and where he begins to quote him.
Whence things have their origin,
Thence also their destruction happens,
As is the order of things;
For they execute the sentence upon one another
- The condemnation for the crime -
In conformity with the ordinance of Time.
In the fourth and fifth line a more fluent translation is given for what is usually rendered rather cryptic by something like "giving justice and reparation to one another for their injustice."
The fragment describes the battle between the elements (or of things in general), which accounts for the origin and destruction of things.
It is certainly important that we possess one text from Anaximander's book. On the other hand, we must recognize that we know hardly anything of its original context, as the rest of the book has been lost. We do not know from which part of his book it is, nor whether it is a text the author himself thought crucial or just a line that caught one reader's attention as an example of Anaximander's poetic writing style.
Perhaps a better way of understanding what Anaximander has to say is to study carefully the doxography, which goes back to people like Aristotle and Theophrastus, who probably have had Anaximander's book before their eyes, and who tried to reformulate what they thought were its central claims.
The origin of the cosmos
The Boundless seems to have played a role in Anaximander's account of the origin of the cosmos. Its eternal movement is said to have caused the origin of the heavens. Elsewhere, it is said that "all the heavens and the worlds within them" have sprung from "some boundless nature". A part of this process is described in rather poetic language, full of images, which seems to be idiosyncratic for Anaximander: "a germ, pregnant with hot and cold, was separated [or: separated itself] off from the eternal, whereupon out of this germ a sphere of fire grew around the vapor that surrounds the earth, like a bark round a tree" (DK 12A10). Subsequently, the sphere of fire is said to have fallen apart into several rings, and this event was the origin of sun, moon, and stars.
Astronomy - The earth floats unsupported in space
Anaximander boldly asserts that the earth floats free in the center of the universe, unsupported by water, pillars, or whatever. This idea means a complete revolution in our understanding of the universe. Obviously, the earth hanging free in space is not something Anaximander could have observed. Apparently, he drew this bold conclusion from his assumption that the celestial bodies make full circles. More than 2500 years later astronauts really saw the unsupported earth floating in space and thus provided the ultimate confirmation of Anaximander's conception.
Why the earth does not fall
We may assume that Anaximander somehow had to defend his bold theory of the free-floating, unsupported earth against the obvious question of why the earth does not fall. Aristotle's version of Anaximander's argument runs like this: "But there are some who say that it (viz. the earth) stays where it is because of equality, such as among the ancients Anaximander. For that which is situated in the center and at equal distances from the extremes, has no inclination whatsoever to move up rather than down or sideways; and since it is impossible to move in opposite directions at the same time, it necessarily stays where it is." (De caelo)
Conclusion
Anaximander was one of the greatest minds that ever lived By speculating and arguing about the 'Boundless' he was the first metaphysician.
Anaximenes
Anaximenes (d. 528 BCE) was the third Greek philosopher in canonical lists of successions, and like his predecessors Thales and Anaximander, an inhabitant of Miletus.
He was said to be the student of Anaximander, and he is best known for his doctrine that air is the source of all things.
Air as source of all things
“Air is the source of all things”: this claim contrasts with the view of Thales that water was the source, and with the view of Anaximander that all things came from an unspecified boundless stuff.
He seems to have held that at one time everything was air. In one region the air was acted upon by natural forces to be transformed into other materials which came together into an organized world, in which we now live.
Air can be thought of as a kind of neutral stuff that is found everywhere, and is hence available to participate in physical processes. It is also associated with the soul-sometimes portrayed as the breath of life in early Greek literature-and hence with life and intelligence.
Anaximenes provides an interesting account of natural change: “[Air] differs in essence in accordance with its rarity or density. When it is thinned it becomes fire, while when it is condensed it becomes wind, then cloud, when still more condensed it becomes water, then earth, then stones. Everything else comes from these.”
Using two contrary processes of rarefaction and condensation, Anaximenes explains how air is part of a series of changes from fire to air to wind to cloud to water to earth to stones. Anaximenes provides a crude kind of empirical support by appealing to a simple experiment: if one blows on one's hand with the mouth relaxed, the air is hot; if one blows with pursed lips, the air is cold.
Material Monism
Most commentators, following Aristotle, understand Anaximenes' theory of change as presupposing Material Monism. According to this theory there is only one substance, in this case air, from which the whole world and everything in it are composed. The several stuffs: wind, cloud, water, etc., are only modifications of the real substance that is always and everywhere present.
Pythagoras
Mathematics
The practical skill of land measurement was invented in Egypt because of the necessity frequently to remeasure plots of land after destructive inundations.
Egypt was believed to be the source of much wisdom and reports tell us that many Greeks, including Thales, Pythagoras, Democritus, and Euclid, visited that ancient land to see the wonders for themselves.
“The Master said so”
Pythagoras (fl. 530 BCE) must have been one of the world's greatest men, but he wrote nothing, and it is hard to say how much of the doctrine we know as Pythagorean is due to the founder of the society and how much is later development.
It is also hard to say how much of what we are told about the life of Pythagoras is trustworthy; for a mass of legend gathered around his name at an early date. Sometimes he is represented as a man of science, and sometimes as a preacher of mystic doctrines, and we might be tempted to regard one or other of those characters as alone historical.