The Philosophy Book

94 THOMAS AQUINAS

the latter’s thinking. For Aquinas, as
a Christian thinker, human beings
are only one type of the various
sorts of beings that are capable of
knowing things intellectually: souls
separated from their bodies in the
afterlife, angels, and God himself
can also do this. These other
knowing beings do not have
to acquire knowledge through the
senses. They can directly grasp
the definitions of things. This
aspect of Aquinas’s theory has
no parallel in Aristotle, but it is a
coherent development of Aristotle’s
principles. Once again Aquinas
is able to hold Christian beliefs
without contradicting Aristotle,
but going beyond him.

The human soul
According to Aristotle, the intellect
is the life-principle or “soul” of a
human being. All living things have
a soul, he believes, which explains
their capacity for different levels of

what he calls “life-activity”, such

as growing and reproducing, for

plants; moving, sensing, seeking,

and avoiding, for animals; and

thinking for humans.

Aristotle believes that “form” is

what makes matter into the thing

that it is. Within the human body,

this form is the soul, which makes

the body into the living thing that

it is by giving it a particular set of

life-activities. As such, the soul is

tied to the body, and so Aristotle

thinks that, even in the case of

humans, the life-soul survives only

so long as it animates a body, and

at death it perishes.

Aquinas follows Aristotle’s

teaching about living things and

their souls, and he insists that a

human being has just one form:

his or her intellect. Although other

13th- and 14th-century thinkers

also adopted the main lines of

Aristotle’s view, they cut the

connection Aristotle had made

between the intellect and the body,

so they could accommodate the

Christian teaching that the human

soul survives death. Aquinas,

however, refuses to distort

Aristotle’s position. This made it

far more difficult for him to argue—

as he did—for the immortality of

the human soul, in yet another

example of his resolve to be a good

Aristotelian, and philosopher, while

remaining a faithful Christian.

After Aquinas

Since the Middle Ages, Aquinas

has come to be regarded as the

official orthodox philosopher of

the Catholic Church. In his own

time, when translations of Greek

philosophy were being made from

Arabic, complete with Arabic

commentaries, he was one of the

thinkers keenest to follow Aristotle’s

train of philosophical reasoning,

even when it did not fit neatly with

Christian doctrine. He always

caused this newton’s cradle

to swing. But does the

existence of the universe

itself have a cause?

The laws of cause and effect lead us to look for the
cause of any event, even the beginning of the universe.
Aristotle supposed that God set the universe into
motion, and Aquinas agreed, but added that the
“Prime Mover”—God—must itself be uncaused.

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