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The Pre-Socratics
Early civilizations
Began in the Levant region of southwest Asia. Other regions
around the world soon followed. The emergence of civilization is
associated with Agricultural Revolution, which occurred in
various locations between 8,000 and 5,000 BCE. This revolution
marked the beginning of stable agriculture and animal
domestication, which enabled economies and cities to develop
increasingly large population, division of labor, specialization,
development of writing…and philosophy!
Philosophy Timeline
Birth of Christ
8000 BCE
5000 BCE
600 BCE
600 CE
Present
1500 CE
1945-50
Civilization begins (?)
Ancient Philosophy
Philosophy Begins
Modern Philosophy
Begins
Medieval Philosophy
Post-Modern
Philosophy
Modern Philosophy
2012
The pre-Socratics were 6Th and 5Th century BCE Greek thinkers
Thales of Miletus (624-546 B.C.E) First Western Philosopher
Anaximander of Miletus (610-546 B.C.E)
Anaximenes of Miletus (585-528 B.C.E)
Pythagoras (582-496 B.C.E)
Xenophanes (570-470 B.C.E)
Leucippus (c550 B.C.E)
Heraclitus (535-475 B.C.E)
Parmenides of Elea (510-440 B.C.E)
Anaxagoras (500-428 B.C.E)
Zeno of Elea (490-430 B.C.E)
Empedocles (490-430 B.C.E)
Democritus (460-370 B.C.E)
Protagoras (481-420 B.C.E)
Diogenes (412-323 B.C.E)
*Why were they called “pre-Socratics”?
 Socrates is such an important figure in Western philosophy
that we divide ancient philosophy into classical philosophers and
pre-Socratic philosophers.
Socrates lived c. 469 BC – 399 BC
Pre-Socratic
 Introduced a new way of thinking about the world:
 At that time Greek myths explained the origins of the universe
and of man: personifications of Earth and Sky mating and
produced land, mountains, and seas.
 Mythology explained the nature of the world by making up
fantastic stories.
 The early Greek, Pre-Socratic philosophers attempted to explain
the world around them in more natural terms than those who
relied on mythological explanations.
Thales of Miletus (624-546 B.C.E)
First philosopher in the West
first who studied astronomy.
Foretold the eclipses and motions of the sun in 585.
Divided the year into 365 days.
Measured pyramids by watching their shadows: Wait till your shadow is
equal to your height and apply *Pythagorean theorem*.
Main doctrine: He asserted water to be the principle of all things: at
low temperature, water becomes rock, at very high temperature air.
Water is essential for life of all organisms.
Physical things take the form of either solid, or liquid, or gas. Since water
can assume all these forms it is possible that everything is a form of water.
landmass ends at water’s edge; so, earth is floating on water.
Continues
…Thales
Of course he was wrong. Today we know that NOT everything is water.
What is important to learn from Thales’ statement has more to do with
the kinds of questions: If “everything is water” was his answer, then the
question must have been something like this: What is the one,
fundamental thing of which all other things are composed? This question
tells us several things about what he must have believed:
he realized that there must be one fundamental element that makes up
all matter, just like science today.
since what we perceive through the senses is not one thing, he must
have realized that mere observation cannot afford us knowledge of the
world. He must have realized that to understand nature it is necessary to
think outside the box: observation + reasoning. This marked a leap
forward from mythology, which merely made up stories.
Anaximander (c. 610 – c. 546 BC)
student of Thales
invented the sundial, he also made clocks.
Earth cannot float on water. Where does water float on? What
supports that water that supports the earth? So, he believed the earth is
unsupported, hanging in space.
had no theory of gravity to explain what holds the earth, but he argued
that the force of opposites held it there.
The principle and primary element of all things was the
Unlimited or boundless, no exact definition. Single formless
substance that can take various forms.
Undefined substance.
the Unlimited is not itself a particular kind of thing, like water.
Anaximander’s odd concept of the “Unlimited” actually is not too far
from our contemporary view that “energy” is the ultimate stuff.
Anaximenes (b. 585 BCE, d. 528 BCE)
 Student of Anaximander
 dismissed the theory of Anaximander: earth must be supported by
something—by air.
said that the principle of everything was the air, “As our souls, being
air, hold us together, so breath and air embrace the entire universe.”
disagrees with Thales that water is the ultimate basis of reality;
Does not agree with Anaximander that the source of all things can be
some vague, poetic entity such as the Unlimited.
Air is all around us. It is necessary for life to breathe it. It fills the sky,
and upon it floats the earth.
He said the three elements, earth, fire and water, arose from the air:
condensation and rarefaction. Pure air is the most rarefied
substance, but it can condense into heavier and heavier forms.
according to degree of condensation—fire, wind, clouds, water, and
earth are formed.
Pythagoras (582-496 BCE)
Pythagoras wrote books on Education, on Politics, and on Natural
Philosophy.
carried geometry to perfection, when he discovered that the square of the
hypotenuse of a right-angled triangle is equal to the squares of the sides
containing the right angle.
Introduced the idea of “square” and “cube” of a number, applying
geometrical concepts to arithmetic.
that the soul is something different from life and is immortal.
that the soul of man is divided into three parts: intuition, reason , and
mind.
Enormously Influenced Plato.
The nature of reality is constituted by numbers/proportions.
Xenophanes (570-470 BCE)
He wrote philosophical poems and disputed the things Hesiod and Homer
said about the Gods.
His doctrine was, that there were four elements of existing things.
He thought that the clouds were produced by the vapor that was borne
upwards from the sun.
That God was in no respect resembling man:
But if (horses) or cows or lions had hands
To draw and produce works of art as men do,
Horses would draw the figures of gods like horses
And cows like cows, and they would make their bodies Just as the
form which they each have
themselves. Ethiopians say that their gods are snub-nosed and
black, and Thracians that theirs have blue eyes and red hair.
Empedocles (490-430 BCE)
Sicilian philosopher pupil of Pythagoras.
It is said that he once went up to mount Etna and leaped into its crater to
prove he was a god.
that there were four elements, FIRE, WATER, EARTH, and AIR. And that
it is friendship by which they are united, and discord by which they are
separated.
that the sun is a vast assemblage of fire, and that it is larger than the
moon.
that the soul inhabits every kind of form of animals and plants.
Leucippus (c550 BCE)
Democritus (460-370 BCE)
his principal doctrines were, that all things were infinite, and were
interchanged with one another.
that the universe was a vacuum, and full of bodies; also that the worlds
were produced by bodies falling into the vacuum.
that the nature of the stars originated in motion.
he was the first philosopher who spoke of atoms as principles.
Here is how Aristotle, who had much to say about Democritus, described his theory:
“According to the theory of Democritus it is the nature of the eternal objects to be
tiny substances infinite in number. Accordingly, he postulates also a place for them
that is infinite in magnitude, which he designates by these names—the void, the
nothing and the infinite; whereas he speaks of each individual atom as the yes-thing,
the dense, and being. He conceives them as so small as to elude our senses, but as
having all sorts of forms, shapes, and different sizes. Treating these as elements, he
conceives of them as combining to produce visible and otherwise perceptible
objects.”
…ATOMISM
That atoms and the vacuum were the beginning of the universe.
Nothing was created out of nothing, and that nothing was destroyed so as to
become nothing. “1St law of thermodynamics: Energy can be neither created nor
destroyed.”
That the atoms produced all the combinations that exist; fire, water, air, and earth.
For Democritus, the material objects evident to our senses were all composed of
atoms. They were eternal, uncreated entities. They could never be destroyed, only
recombined in a different manner.
In such a mechanistic world, where everything happens in machine-like fashion,
there is no room for the exercise of free will. This view is called determinism.
Determinism is the belief that every event has a cause. Free choices are thought of
as choices that are not rigidly caused, as choices that could have been different. In a
mechanistic world, however, everything that happens is determined by previous
causes to happen in precisely the way that it does, and in no other way. My choices
are not free because, like everything else, they are brought about by the prior
movements of atoms, movements which were themselves
Heraclitus (535-475 BCE)
everything is constantly changing; nothing is permanent.
Everything is a coming together of opposites: the path up to the mountain and the
path down are the same path; the young you and the old you are the same you; if I say
my glass is half empty and you say it’s half full we agree with each other.
that everything flows on like a river—everything is a flux.
That "You can't step into the same river twice”.
Nothing is permanent. Everything changes constantly. Things as well as men are
never the same for two moments…
he appears to identify reality with one of the four elements, fire. “There is exchange
of all things for fire and of fire for all things…”
Universe is made of fire. Fire seems a thing/object, but in reality is a process in
perpetual motion.
Change is the law of life, and there is nothing definite in the universe.
“This universe, which is the same for all, has not been made by any god or man, but it
always has been, is, and will be—an ever-living fire, kindling itself by regular
measures and going out by regular measures.”
Parmenides of Elea (510-440 BCE)
If Heraclitus said that all was change, though change according to regular
patterns, Parmenides said nothing changes, that everything is permanent,
that everything is what he called Being.
If what is real, Being, is what can be thought or said, and if not-being
cannot be thought or said, then reality is only Being. There is no not-being.
Being is eternal. It was not created nor can it be destroyed.
Everything that Is did not “become” what it is, for then it would have had
to not-be before it was.
Nothing comes out of nothing: everything must always have existed.
Being is One
Reality must be/universe must be one single unchanging entity.
When we experience change is because it occurs within an unchanging
system.
It is a fixed and frozen unity, always has been, and always will be that way.
Anaxagoras (500-428 BCE)
that the sun was a mass of burning iron, greater than Peloponnesus, and
that the moon contained houses, and also hills and ravines
The winds he thought were caused by the rarification of the atmosphere,
which was produced by the sun. Thunder, he said, was produced by the
collision of the clouds; and lightning by the rubbing together of the clouds.
Earthquakes were produced by the return of the air into the earth.
All animals he considered were originally generated out of moisture, and
heat, and earthy particles: and subsequently from one another.
(EVOLUTION)
It is said that he was persecuted for impiety because he said that the sun
was a fiery ball of iron.
Zeno of Elea (490-430 BCE)
Zeno's paradoxes are a set of philosophical problems to
support his teacher’s, Parmenides, doctrine that "all is one"
and that, contrary to the evidence of our senses, the belief
in plurality and change is mistaken.
motion is illusory.
Achilles and the Tortoise:
“ In a race, the quickest runner can never overtake the
slowest, since the pursuer must first reach the point whence
the pursued started, so that the slower must always hold a
lead.”
Dialogue by Lewis Carroll:
The Tortoise challenged Achilles to a race, claiming that he would win as long as
Achilles gave him a small head start. Achilles laughed at this, for of course he
was a mighty warrior and swift of foot, whereas the Tortoise was heavy and slow.
“How big a head start do you need?” he asked the Tortoise with a smile.
“Ten meters,” the latter replied.
Achilles laughed louder than ever. “You will surely lose, my friend, in that
case,” he told the Tortoise, “but let us race, if you wish it.”
“On the contrary,” said the Tortoise, “I will win, and I can prove it to you by a
simple argument.”
“Go on then,” Achilles replied, with less confidence than he felt before. He
knew he was the superior athlete, but he also knew the Tortoise had the sharper
wits, and he had lost many a bewildering argument with him before this.
“Suppose,” began the Tortoise, “that you give me a 10-meter head start. Would
you say that you could cover that 10 meters between us very quickly?”
“Very quickly,” Achilles affirmed.
“And in that time, how far should I have gone, do you think?”
“Perhaps a meter – no more,” said Achilles after a moment's thought.
“Very well,” replied the Tortoise, “so now there is a meter
between us. And you would catch up that distance very quickly?”
“Very quickly indeed!”
“And yet, in that time I shall have gone a little way farther, so
that now you must catch that distance up, yes?”
“Ye-es,” said Achilles slowly.
“And while you are doing so, I shall have gone a little way
farther, so that you must then catch up the new distance,” the
Tortoise continued smoothly.
Achilles said nothing.
“And so you see, in each moment you must be catching up the
distance between us, and yet I – at the same time – will be adding
a new distance, however small, for you to catch up again.”
“Indeed, it must be so,” said Achilles wearily.
“And so you can never catch up,” the Tortoise concluded
sympathetically.
“You are right, as always,” said Achilles sadly – and conceded
the race.
In other words...
Suppose I wish to cross this room. First, of course, I must cover half the distance.
Then, I must cover half of the half. Then, I must cover half the remaining distance.
Then I must cover half the remaining distance . . . and so on forever. The consequence
is that I can never get to the other side of the room.
What this actually allegedly shows is to that all motion impossible, for before I can
cover half the distance I must cover half of half the distance, and before I can do that I
must cover half of half of half of the distance, and so on, so that in reality I can never
move any distance at all, because doing so involves moving an infinite number of
small intermediate distances first.
The arrow paradox
“ If everything when it occupies an equal space is at rest, and if that which is in
locomotion is always occupying such a space at any moment, the flying arrow is
therefore motionless.”
For motion to occur, an object must change the position which it
occupies. For example, consider an arrow in flight. In any one instant of
time, the arrow is neither moving to where it is, nor to where it is not. It
cannot move to where it is not, because no time elapses for it to move
there; it cannot move to where it is, because it is already there. In other
words, at every instant of time there is no motion occurring. If
everything is motionless at every instant, and time is entirely composed
of instants, then motion is impossible.
Protagoras (481-420 BCE)
in every question there were two sides to the argument exactly
opposite to one another: "Man is the measure of all things”
“Concerning the Gods, I am not able to know to a certainty whether
they exist or whether they do not. For there are many things which
prevent one from knowing, especially the obscurity of the subject, and
the shortness of the life of man.”
he was banished by the Athenians. And his books were burnt in the
market-place.
Instituted contests of argument, and charged money to teach how to
win arguments. (sophism).
Diogenes of Sinope "The Cynic" (c412-323 BCE)
He said that in reality everything was a combination of all things:
that in bread there was meat, and in vegetables there was bread, and so
there were some particles of all other bodies in everything,
communicating by invisible passages and evaporating.
Music and geometry, and astronomy, and all things of that kind, he
neglected, as useless and unnecessary.
maintained that all the artificial growths of society were
incompatible with happiness and that morality implies a return to the
simplicity of nature: "Humans have complicated every simple gift of
the gods.“
When he was asked where he came from, he replied, "I am a citizen
of the world
In Conclusion
The Pre-Socratics have offered solutions to one of the many fundamental
questions of life, What is the nature of reality?
they questioned the ordinary concept of reality.
their explanations of the world were free from reference to gods and
spirits and other personal forces. The Pre-Socratics demythologized
nature.
They invented the concept of nature as an impersonal place, a concept
that we all take for granted today.
Realized that our senses often cannot afford us a true picture of reality
and that there was a deeper reality to existence, different from the way that
the world appeared to us in our daily lives.
Introduced notions that were influential within both philosophy and
later science. Particular theories, for example, were precursors to their later
scientific cousins: theories of evolution, atomism were developed. The very
idea of a natural law also arose from their speculations.
…and then comes Socrates.