Ancient Greek Philosophers
School of Athens - Raphael Sanzio
BIRTH OF PHILOSOPHY
• Philosophy originated in the Greek
city states along the coast of Asia
Minor around 600 BC
– Because they were not as
bound by tradition as city-states
on mainland Greece
– Because they were also
constantly in touch with the
ancient science and speculation
of the Middle East
– They were, in short, more open
to intellectual innovation and
speculation than counterparts
on the mainland
• Ancient Philosophy
• The early Greek philosophers saw the world around them and
asked questions about it. Instead of attributing its creation to
anthropomorphic gods, they sought rational explanations.
• One idea the Pre-Socratic philosophers had was that there
was a single underlying substance that held within itself
principles of change.
• This underlying substance and its inherent principles could
become anything. In addition to looking at the building blocks
of matter, the early philosophers looked at the stars, music,
and number systems. Later philosophers focused entirely on
conduct or ethics.
• Instead of asking what made the world, they asked what was
the best way to live.
• The Western philosophical tradition began in
ancient Greece in the 6th century BCE. The
first philosophers are called “Presocratics”
which designates that they came before
• The Presocratics were from either the eastern
or western regions of the Greek world.
Athens — home of Socrates, Plato an
Aristotle — is in the central Greek region and
was late in joining the philosophical game.
• The Presocratic’s most distinguishing feature
is emphasis on questions of physics;
indeed, Aristotle refers
“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
Three philosophers of Miletus
believed in a single basic
• Thales = water
• Anaximander = divine matter; boundless
• Anaximenes = air
• Parmenedes: all is permanent
• Heraclitus: all is in flux
• Basic elements: air, water, earth, fire
• Empedocles: Source of nature cannot be a single element
• Anaxagoras: seeds ordered by intelligence
• Anaximander thought the principle
of all things was infinity.
• He also said the moon borrowed
its light from the sun, which was
made up of fire.
• He made a globe and, according to
Diogenes Laertes was the first to
draw a map of the inhabited world.
• Anaximander is credited with
inventing the gnomon (pointer) on
• Empedocles of Acragas (c. 495-435 B.C.) was
known as a poet, statesman, and physician, as
well as philosopher.
• Empedocles encouraged people to look upon
him as a miracle worker. Philosophically he
believed in the four elements.
• Heraclitus (fl. 69th Olympiad,
504-501 B.C.) is the first
philosopher known to use the
word kosmos for world order,
which he says ever was and
ever will be, not created by
god or man.
• Heraclitus is thought to have
abdicated the throne of
Ephesus in favor of his
brother. He was known as
Weeping Philosopher and
Heraclitus the Obscure.
• Parmenides (b c. 510 B.C.) was a
• He argued against the existence
of a void, a theory used by later
philosophers in the expression
"nature abhors a vacuum,"
which stimulated experiments to
• Parmenides argued that change
and motion are only delusions.
The Pythagorean School
• Probably the most famous of the early Greek
philosophers that are known collectively as
the Pre-Socratics is the 6th century B.C.
philosopher Pythagoras, who may have
actually lived and may have invented the
theorem named for him -- or not.
• Anyone who can recall math classes will
remember the first lessons of plane geometry
that usually start with the Pythagorean
theorem about right-angled triangles:
a²+b²=c². In spite of its name, the Pythagorean
theorem was not discovered by Pythagoras.
• This shows how Pythagoras’ formulation
immediately led to a new mathematical
problem, namely that of incommensurables.
At his time the concept of irrational numbers
was not known and it is uncertain how
Pythagoras dealt with the problem.
• From Pythagoras we observe that an answer
to a problem in science may give raise to new
• For each door we open, we find another
closed door behind it.
• Greek Philosophers
– Pythagoras- universe followed the same laws that
govern music & numbers
• Pythagorean Theorem- determine the length of the
sides of a triangle