The Philosophy Book

THE ANCIENT WORLD 61

Does it fly?

Does it havefeathers? Does it have scales?

Yes

Yes Yes

No

No No

Aristotle’s classification of living things is
the first detailed examination of the natural world.
It proceeds from general observations about the
characteristics shared by all animals, and then
subdivides into ever more precise categories.

as its skin, fur, feather, or scales,
but also a matter of what it does,
and how it behaves—which, for
Aristotle, has ethical implications.
To understand the link with
ethics, we need first to appreciate
that for Aristotle everything in
the world is fully explained by four
causes that fully account for a
thing’s existence. These four causes
are: the material cause, or what a
thing is made of; the formal cause,
or the arrangement or shape of a

Linnaeus and Cuvier

have been my two gods,

though in very different

ways, but they were mere

schoolboys to old Aristotle.

Charles Darwin

thing; the efficient cause, or how

a thing is brought into being; and

the final cause, or the function or

purpose of a thing. And it is this

last type of cause, the “final cause”,

that relates to ethics—a subject

which, for Aristotle, is not separate

from science, but rather a logical

extension of biology.

An example that Aristotle gives

is that of an eye: the final cause

of an eye—its function—is to see.

This function is the purpose, or

telos, of the eye—telos is a Greek

word that gives us “teleology”, or

the study of purpose in nature. A

teleological explanation of a thing

is therefore an account of a thing’s

purpose, and to know the purpose

of a thing is also to know what a

“good” or a “bad” version of a thing

is—a good eye for example, is one

that sees well.

In the case of humans, a “good”

life is therefore one in which we

fulfill our purpose, or use all the

characteristics that make us

human to the full. A person can be

considered “good” if he uses the

characteristics he was born with,

and can only be happy by using all

his capabilities in the pursuit of

virtue—the highest form of which,

for Aristotle, is wisdom. Which

brings us full circle back to the

question of how we can recognize

the thing that we call virtue—and

for Aristotle, again, the answer is

by observation. We understand the

nature of the “good life” by seeing

it in the people around us.

The syllogism

In the process of classification,

Aristotle formulates a systematic

form of logic which he applies

to each specimen to determine ❯❯