2. OGroup of early Greek philosophers,
most of whom were born
before Socrates, whose attention to
questions about the origin and
nature of the physical world has led
to their being called cosmologists or
naturalists.
Pre-Socratics
3. ZENO of Elea
• Zeno is especially known for
his paradoxes that contributed to the
development of logical and mathematical
rigour and that were insoluble until the
development of precise concepts
of continuity and infinity.
“If what is had no magnitude, it would not
even be…”
• He sought to controvert the
commonsense belief in the existence of
“the many”.
• Zeno made use of three premises: first, that
any unit has magnitude; second, that it is
infinitely divisible; and third, that it is
indivisible.
4. PARMENIDES
On Nature
This poem tells of Parmenides journey to visit a
Goddess in search of wisdom.
• Parmenides believed that the whole
universe, all that exists, is timeless
and unified.
• (Born c. 515 BCE), Greek philosopher
of Elea in southern Italy who
founded Eleaticism,
• Teacher and Author
5. HERACLITUS/Heracleitus
• Heraclitus, also known as
Heraclitus the Black, the
Obscure, and the Weeping
“You cannot step in the same river twice.”
• He suffered from dropsy,
accumulation of fluid under the
skin.
“Everything flows.”
• (Born c. 540 BCE, Ephesus, Anatolia [now
Selçuk, Turkey]—died c.480),
• He was primarily concerned with
explanations of the world around him.
6. Thales of MILETUS
Who Was Thales?
Ancient Greece was famous for its
many great philosophers, but who
was the first? Most scholars, including
most ancient Greek philosophers,
name Thales of Miletus (in Ionia, or
western Turkey) as the first
philosopher. This 6th century BCE
thinker is, in fact, considered the
'Father of Philosophy.' We know very
little about Thales the man, and none
of his writings survive. However,
thanks to subsequent ancient Greek
philosophers who were familiar with
Thales's theories, particularly
Aristotle, we know a few key points
about this great intellectual.
7. Historical Context and
Influence
O Circa 624 BCE, Thales was born into a Greek
culture that explained the world through
mythology. For example, according to
mythology, earthquakes occurred because
Poseidon, the god of the sea and
earthquakes, was angry. Thales was the first,
however, to consider that there might be
natural explanations for such phenomena.
Because of this paradigm-shifting concept,
Thales is considered the foremost of the
famous Seven Wise Men, Pre-Socratic Greek
sages who became famous amongst later
philosophers for their wisdom in logic, law,
ethics, and science.
8. Thales's Theories
O Thales seemed to be interested in many subjects, though we only have
fragments of his intellectual achievements. He was likely a statesman or
a leader of some sort. He made scientific observations of weather
phenomena, and with the help of science and math, he was able to
advance techniques in sea navigation. Combining math and science
once again, he also became skilled in astronomy and was even able to
predict an eclipse. Thales approached each of these subjects searching
for rational, instead of mythological, explanations.
O A prominent, though vague, tenet of Thales's philosophy was the idea
that everything on Earth has a soul. By soul, Thales meant the capacity
for change or movement. The phrase, 'all things are full of gods', which
Thales may or may not have actually said, is nevertheless famously
associated with this theory of soul and movement. By this concept,
Thales meant that there are natural laws inherent in natures that
determine how a thing functions and changes. Notice again that Thales
turned to natural law instead of mythology and divine intervention to
explain how the world worked.
9. PHYTAGORAS
The pre-Socratic Greek philosopher
Pythagoras must have been one of the
world's greatest persons, 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.
10. O The truth is that there is no need to reject either of the
traditional views. The union of mathematical genius
and mysticism is common enough. Originally from
Samos, Pythagoras founded at Kroton (in southern
Italy) a society which was at once a religious
community and a scientific school. Such a body was
bound to excite jealousy and mistrust, and we hear of
many struggles. Pythagoras himself had to flee from
Kroton to Metapontion, where he died.
O It is stated that he was a disciple of Anaximander, his
astronomy was the natural development of
Anaximander's. Also, the way in which the
Pythagorean geometry developed also bears witness
to its descent from that of Miletos. The great problem at
this date was the duplication of the square, a problem
which gave rise to the theorem of the square on the
hypotenuse, commonly known still as the Pythagorean
proposition.
11. ANAXIMANDER
Anaximander of Miletus, son of
Praxiades, a fellow-citizen and
associate of Thales.
“The material cause and first
element of things was the Infinite.”
He says it is neither water nor
any other of the so-called
elements, but a substance
different from them which is
infinite, from which arise all the
heavens and the worlds within
them.
12. O Anaximander 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. He originated the world-picture of the open
universe, which replaced the closed universe of the
celestial vault.
O His work will always remain truncated, like the mutilated
and decapitated statue that has been found at the
market-place of Miletus and that bears his name.
Nevertheless, by what we know of him, we may say that
he was one of the greatest minds that ever lived. By
speculating and arguing about the "Boundless" he was
the first metaphysician. By drawing a map of the world
he was the first geographer. But above all, by boldly
speculating about the universe he broke with the ancient
image of the celestial vault and became the discoverer
of the Western world-picture.
13. ANAXIMENES
Anaximenes of Miletus, son of
Eurystratos, who had been an
associate of Anaximander.
“Our soul being air, holds us
together, so do breath and air
encompass the whole world.”
14. O According to the surviving sources on his life,
Anaximenes flourished in the mid 6th century
B.C.E. and died about 528. He is the third
philosopher of the Milesian School of philosophy,
so named because like Thales and Anaximander,
Anaximenes was an inhabitant of Miletus, in
Ionia (ancient Greece). Theophrastus notes that
Anaximenes was an associate, and possibly a
student, of Anaximander's.
O Anaximenes is best known for his doctrine that
air is the source of all things. In this way, he
differed with his predecessors like Thales, who
held that water is the source of all things, and
Anaximander, who thought that all things came
from an unspecified boundless stuff.
