The Philosophy Book

62 ARISTOTLE

whether it belongs to a certain
category. For example, one of the
characteristics common to all
reptiles is that they are cold-blooded;
so, if this particular specimen is
warm-blooded, then it cannot be a
reptile. Likewise, a characteristic
common to all mammals is that
they suckle their young; so, if this
specimen is a mammal, it will suckle
its young. Aristotle sees a pattern
in this way of thinking—that of
three propositions consisting of
two premises and a conclusion, for
example in the form: if As are Xs,
and B is an A, then B is an X.
The “syllogism”, as this form of
reasoning is known, is the first
formal system of logic ever devised,
and it remained the basic model for
logic up until the 19th century.
But the syllogism was more than
simply a by-product of Aristotle’s
systematic classification of the
natural world. By using analytical
reasoning in the form of logic,
Aristotle realized that the power
of reason was something that did
not rely on the senses, and that
it must therefore be an innate
characteristic—part of what it is
to be human. Although we have no
innate ideas, we do possess this

innate faculty, which is necessary

for us to learn from experience.

And as he applied this fact to his

hierarchical system, he saw that

the innate power of reason is what

distinguishes us from all other

living creatures, and placed us at

the top of the hierarchy.

Decline of Classical Greece

The sheer scope of Aristotle’s ideas,

and the revolutionary way in which

he overturns Plato’s theory of Forms,

should have ensured that his

philosophy had a far greater impact

than it did during his lifetime. That

is not to say that his work was

without fault—his geography and

astronomy were flawed; his ethics

supported the use of slaves and

considered women to be inferior

human beings; and his logic was

incomplete by modern standards.

However, what he got right

amounted to a revolution both

in philosophy and in science.

But Aristotle lived at the end of

an era. Alexander the Great, whom

he taught, died shortly before him,

and so began the Hellenistic period

of Greek history which saw a decline

in Athens’ influence. The Roman

Empire was becoming the dominant

power in the Mediterranean, and the

philosophy it adopted from Greece

was that of the Stoics. The rival

schools of Plato and Aristotle—

Plato’s Academy and the Lyceum

Aristotle founded in Athens—

continued to operate, but they

had lost their former eminence.

As a result of this neglect, many

of Aristotle’s writings were lost. It

is believed that he wrote several

hundred treatises and dialogues

explaining his theories, but all that

remain are fragments of his work,

mainly in the form of lectures and

teacher’s notes. Luckily for posterity,

these were preserved by his

followers, and there is enough

contained in them to give a picture

of the full range of his work.

Aristotle’s legacy

With the emergence of Islam in the

7th century CE, Aristotle’s works

were translated into Arabic and

spread throughout the Islamic world,

becoming essential reading for

Middle Eastern scholars such as

Avicenna and Averroes. In Western

Europe, however, Boethius’s Latin

translation of Aristotle’s treatise on

logic (made in the 6th century CE)

remained the only work of Aristotle’s

Every action must be

due to one or other of

seven causes: chance,

nature, compulsion,

habit, reasoning,

anger, or appetite.

Aristotle

Therefore Socrates

is mortal.

All men are mortal. Socrates is a man.

“Socrates is mortal” is the undeniable conclusion
to the most famous syllogism in history. Aristotle’s
syllogism—a simple deduction from two premises
to a conclusion—was the first formal system of logic.