We know almost nothing about Thales of Miletus. Later
generations told many anecdotes about this wise man,
but it is difficult to verify the reliability of these
stories. What seems certain, however, is that he
predicted the solar eclipse of 28 May 585, which was
remembered because the Lydian king Alyattes and the
Median leader Cyaxares were fighting a battle on that
day. Another reliable bit of information is that he
did geometrical research, which enabled him to measure
the pyramids. However, his most important contribution
to European civilization is his attempt to give
rational explanations for physical phenomena. Behind
the phenomena was not a catalogue of deities, but one
single, first principle. Although his identification
of this principle with water is rather unfortunate,
his idea to look for deeper causes was the true
beginning of philosophy and science. Thales died after
547.

Thales was not the only one who was
looking for a first cause. Pythagoras of Samos
(c.570-c.495) did the same. According to legend, he
left his country and studied with the wise men of
Egypt, but was taken captive when the Persian king
Cambyses invaded the country of the Nile (525). He now
became a student of the Chaldaeans of Babylon and the
Magians of Persia. Some even say that he visited the
Indian Brahmans, because Pythagoras believed in
reincarnation. At the end of the sixth century, he
lived in southern Italy, where he founded a community
of philosophers. In his view, our world was governed
by numbers, and therefore essentially harmonious.
Heraclitus was a rich man from Ephesus and lived
c.500, during the Persian occupation of his home town.
His philosophical work consists of a series of
cryptical pronouncements that force a reader to think.
Unfortunately, a great part of his work is lost, which
makes it very difficult to reconstruct Heraclitus'
ideas. It seems certain, however, that he thought that
the basic principle of the universe was the logos,
i.e. the fact that it was rationally organized and
therefore understandable. Bipolar oppositions are one
form of organization, but the sage understands that
these oppositions are just aspects of one reality.
Fire is the physical aspect of the perfect logos.
Parmenides of Elea was a younger
contemporary
of Heraclitus of Ephesus, but he lived at the opposite
end of the Greek world: in Italy. Both men were
intrigued by the immense variety of phenomena, but
where Heraclitus discerned order in the chaos,
Parmenides pointed out that the endless variety and
eternal changes were just an illusion. In a long poem,
which partially survives, he opposed 'being' to 'not
being', and pointed out that change was impossible,
because it would mean that something that was 'not
being' changed into 'being', which is absurd. In other
words, we had to distrust our senses and rely solely
on our intellect. The result was a distinction between
two worlds: the unreal world which we experience every
day, and the reality, which we can reach by thinking.
This idea was to prove one of the most influential in
western culture.
One of the solutions to the
problem postulated by Parmenides of Elea, was the
hypothesis of Democritus of Abdera: matter is made up
from atoms. There was no real evidence for this idea
(which was not completely new), but it explained why
change was possible. The atoms were always moving and
clustering in various, temporary combinations.
Therefore, things seemed to change, but 'not being'
never changed into 'being'. (It was assumed that 'not
being' was a vacuum, which means that it is in fact
not a 'not being' because a vacuum exists in four
dimensions.) The consequence of this idea is that we
are allowed to use our senses, although Democritus
warns us to be careful.
Thales,
Pythagoras, Heraclitus,
Parmenides, and Democritus had
been trying to explain the diversity of nature. The
object of the studies of the Athenian philosopher
Socrates (469-399) was altogether different: he was
interested in ethics. It was his axiom that no one
would knowingly do a bad thing. So knowledge was
important, because it resulted in good behavior. If we
are to believe his student Plato, Socrates was always
asking people about what they knew, and invariably
they had to admit that they did not really understand
what was meant by words like courage, friendship, love
etc. Socrates was never without critics. The comic
poet Aristophanes ridiculed him in The clouds, and
when his pupil Alcibiades had committed high treason,
Socrates' position became very difficult. He was
forced to drink hemlock after a charge that he had
corrupted the youth. Among his students were
Antisthenes, Plato and Xenophon.
In the decade
after the death of Socrates, Antisthenes (c.445-c.365)
was the most important Athenian philosopher. Like his
master, he tried to find out what words mean, but he
was convinced that it was not possible to establish
really good definitions (which brought him into
conflict with Plato). He did only partially agree with
Socrates that someone who knew what was good, would
not do a bad thing. Antisthenes added that one also
had to be strong enough ("as strong as Socrates") to
pursue what was good. Therefore, Antisthenes
recommended physical training of all kinds, and wanted
his students to refrain from luxury. His most famous
pupil was Diogenes of Sinope
The Athenian
philosopher Plato (427-347)
is usually called a pupil
of Socrates, but his ideas are no less inspired by
Parmenides. Plato accepted the world of the phenomena
as a mere shadow of the real world of the ideas. When
we observe a horse, we recognize what it is because
our soul remembers the idea of the horse from the time
before our birth. In Plato's political philosophy,
only wise men who understand the dual nature of
reality are fit to rule the country. He made three
voyages to Syracuse to establish his ideal state, both
times without lasting results. Plato's hypothesis that
our soul was once in a better place and now lives in a
fallen world made it easy to combine platonic
philosophy and Christianity, which accounts for the
popularity of Platonism in Late Antiquity. One
element, however, was not acceptable: the idea of
platonic love - a homosexual relation with pedagogical
aspects.
Diogenes of Sinope (c.412-c.323) was
a student of Antisthenes. Both men are called the
founder of the school that is known as Cynicism. The
essential point in this world-view is that man suffers
from too much civilization. We are happiest when our
life is simplest, which means that we have to live in
accordance with nature - just like animals. Human
culture, however, is dominated by things that prevent
simplicity: money, for example, and our longing for
status. Like his master, Diogenes refrained from
luxury and often ridiculed civilized life. His
philosophy gained some popularity because he focused
upon personal integrity, whereas men like Plato and
Aristotle of Stagira had been thinking about man's
life and honor as member of a city state - a type of
political unit that was losing importance in the age
of Alexander the Great. However, we can not return to
nature. The Cynics became some sort of jesters,
accepted at the royal courts because their criticism
was essentially harmless.
Plato's most famous
student was the Macedonian scientist Aristotle of
Stagira (384-322). After the death of his master, he
studied biology and accepted a position as teacher of
the Macedonian crown prince Alexander at Mieza. When
the Macedonians subdued Greece, Aristotle founded a
school at Athens. Most of his writings are lost; what
remains are his lecture notes, which were rediscovered
in the first century BCE. During the last decades,
scholars have started to re-examine the fragments of
the lost works, which has led to important changes in
our understanding of Aristotle's philosophy. However,
the accepted view remains that he replaced his
master's speculations with a more down-to-earth
philosophy. His main works are the Prior Analytics(in
which he described the rules of logic), the Physics,
the Animal History, the Rhetorics, the Poetics, the
Metaphysics, the Nicomachean Ethics, and the Politics.
All these books have become classics, and it is not
exaggerated to say that Aristotle is the most
influential philosopher of all ages and the founder of
modern science.
All philosophers are confident
that rational thinking is the road to truth. Except
for Pyrrh of Elis (c.360-c.270BCE), who entertained
some doubts about the quest for knowledge. He argued
that we can not fully comprehend nature, do not know
for certain whether a statement is true or false, and
are unable to build an ethical system on so weak a
fundament. People would be happier if they gave up
these useless intellectual exercises and postponed
their judgment. The result was a conservative
political philosophy, because Pyrrho recommended that,
even though we had no moral absolutes, we should live
by time-honored traditions. The weakness of his system
is, of course, twofold: in the first place, one can
not postpone a judgment forever, because sometimes
action has to be undertaken; in the second place, how
can you be certain that certain knowledge is
impossible? Pyrrho's world-view is called Skepticism,
and may be compared to the postmodernist philosophy of
the 1980's.
We live happiest when we are free from
the pains of life, and a virtuous life is the best way
to obtain this goal. This is, in a nutshell, the view
of the Samian philosopher Epicurus (342-271). In his
opinion, we are unable to understand the gods, who may
or may not have created this world but are in any case
not really interested in mankind. Nor do we know life
after death - if there is an existence at all after
our bodies have decomposed. Therefore, we must not
speculate about gods and afterlife. In Antiquity,
Epicurism was the most popular of all philosophical
schools, a popularity which it partially owed to the
fact that its founder had explained his thoughts in
several maxims, which even the illiterate could
remember. Predictably, Christian philosophers attacked
Epicurus' ideas about the afterlife and divine
providence.

After the conquests of
Alexander, the world was larger than ever, and the
city-state had ceased to be an important political
unit. Like Diogenes of Sinope and Epicurus, Zeno of
Citium (336-264 BCE) ignored traditional values like
prestige and honor, and focused on man's inner peace.
In his view, this was reached when a person accepted
life as it was, knowing that the world was rationally
organized by the logos. A man's mind should control
his emotions and body, so that one could live
according to the rational principles of the world. It
has often been said that Zeno's ideas combine Greek
philosophy with Semitic mysticism, but except for his
descent from a Phoenician town on Cyprus and an
interest in (Babylonian) astronomy, there is not much
proof for this idea. This philosophy, called Stoicism,
became very influential under Roman officials.
Zeno of Citium was succeeded as head of the Stoic
school at Athens by Cleanthes, who was in turn
succeeded by Chrysippus, a native of Soli in Cilicia
(c.279-c.206). His contributions to the development of
philosophy can especially be found in the field of
logic, where he studied paradoxes and the way an
argument should be constructed. He also reflected upon
the use of allegoresis, which is a way to read a text
metaphorically and find hidden meanings (or construct
them). From now on, philosophers started to use the
epics of Homer and the tragedies of Euripides as if
they were philosophical treatises. Finally, Chrysippus
was the man who concluded that if the rational
principle of the universe, the logos, was divine, the
world could be defined as a manifestation of God.
We are ill-informed about the
development of
philosophy after the origin of the Stoa, Epicurism,
Skepticism, Cynicism, Aristoteleanism, and Platonism.
For several reasons, nearly all texts are lost. This
was also the fate of the works of the Stoic sage
Posidonius of Apamea (c.135-51), but his books are
often quoted by other authors. As a philosopher, he
was not an innovator, but applied the theory to
science and scholarship. For example, his Histories
were a philosophical continuation of the World History
of Polybius of Megalopolis. Among his other
publications were treatises in which the Stoic world
view was applied to everyday subjects: On anger, On
virtue, and Consolation. Being more interested in
educating the masses than in theoretical purity, he
often borrowed ideas from other schools. Philosophy
after Posidonius often was a cross-fertilization
between viewpoints (e.g., Plutarch of Chaeronea and
Plotinus).
The charismatic teacher and miracle
worker Apollonius lived in the first century AD. He
was born in Tyana and gave a new interpretation to
Pythagoreanism, which was essentially a combination of
ascesis and mysticism. In his books On astrology and
On sacrifices, he demanded bloodless offerings to the
One God, who needs nothing even from beings higher
than ourselves. This brought Apollonius into conflict
with the religious establishment, but he was
recognized as a great sage and received divine honors
in the third century. Although the Athenian
Philostratus wrote a lengthy Life of Apollonius,
hardly anything is certain about the man who was and
is frequently compared to the Jewish sage and miracle
worker Jesus of Nazareth.
I
n his own age, the Delphian oracle priest Plutarch of Chaeronea
(46-c.122) was immensely popular because he was, like
Posidonius of Apamea, able to explain philosophical
discussions to a general audience. Among his Moral
treatises are treatises like Checking anger, the
useful The art of listening, the fascinating How to
know whether one progresses to virtue, and the
charming Advice to bride and groom. Plutarch also
wrote double biographies, in which he usually compared
a Greek to a Roman (e.g., Alexander and Julius
Caesar). In the epilogue, he analyzed their respective
characters. The result is not only an entertaining
biography, but also a better understanding of a
morally exemplary person, which the reader can use for
his own progress to virtue.
Born in Phrygia,
Epictetus (c.50-c.125 CE) became a slave of the
emperor Nero's courtier Epaphroditus. When he was old,
useless and therefore "freed" from slavery, he had to
make a living and started to teach the Stoic
philosophy, first at Rome and (after the emperor
Domitian had expelled the philosophers in 89) at
Nicopolis in western Greece. Because Epictetus was
able to explain Stoicism in a systematic way and with
an open eye to its practical applications, he had many
students from the rich senatorial order, which ruled
the Roman empire. Among these men were the future
emperor Hadrian and the historian Arrian of Nicomedia,
who published several of his conversations. Epictetus
wrote a Handbook, which is arguably the most popular
book on philosophy that was ever written.
After the age of Posidonius of Apamea, it was not
uncommon that philosophers from one school borrowed
concepts and ideas from other branches of philosophy.
Slowly, the schools were merging, and a new synthesis
(called Neo-Platonism) was created by
Plotinus(205-270). Like Plato, he accepted that our
world was a mere shadow of the world of the ideas,
which was in turn -and this was a novel idea- a shadow
of an even higher world, which was again a shadow of
the One God. In other words, the world has four levels
of reality: God was the highest level, and then there
were the levels of the intellect, the soul, and
matter. (That matter is more real than the speculative
levels of existence, was an unusual idea in
Antiquity.) According to Plotinus, the wise man would
try, by means of ascesis, to free his soul from matter
and unite it with God. Plotinus achieved this mystical
unity several times. His philosophy was adopted by the
fathers of the church Ambrose and Augustine, and was
to remain the philosophical school par excellence
until Aristotle of Stagira was rediscovered in the
twelfth century.