The Philosophy Book

78 AVICENNA

Avicenna’s medical knowledge

was so vast that it won him royal

patronage. His Canon of Medicine

influenced European schools of

medicine until the mid-17th century.

The secret conversation

is a direct encounter

between God and the soul,

abstracted from all

material constraints.

Avicenna

appears as a treatise, On the Soul,
within his Book of Healing, and it
aims to strip away any knowledge
that can possibly be disproved, and
leave us only with absolute truths.
It remarkably anticipates the much
later work of Descartes, the famous
dualist of the 17th century, who also
decided to believe nothing at all
except that which he himself could
know for certain. Both Avicenna
and Descartes want to demonstrate
that the mind or self exists because
it knows it exists; and that it is
distinct from the human body.

The Flying Man
In the Flying Man experiment,
Avicenna wants to examine what
we can know if we are effectively
robbed of our senses, and cannot
depend on them for information.
He asks us each to imagine this:
suppose I have just come into
existence, but I have all my normal
intelligence. Suppose, too, that I am
blindfolded and that I am floating in
the air, and my limbs are separated

from each other, so I can touch

nothing. Suppose I am entirely

without any sensations. None the

less, I will be sure that I myself exist.

But what is this self, which is me?

It cannot be any of the parts of my

body, because I do not know that I

have any. The self that I affirm as

existing does not have length or

breadth or depth. It has no extension,

or physicality. And, if I were able

to imagine, for instance, a hand,

I would not think that it belonged

to this self which I know exists.

It follows from this that the

human self—what I am—is distinct

from my body, or anything physical.

The Flying Man experiment, says

Avicenna, is a way of alerting and

reminding oneself of the existence

of the mind as something other

than, and distinct from, the body.

Avicenna also has other ways

to show that the mind cannot be

something material. Most are

based on the fact that the type of

intellectual knowledge the mind

can grasp cannot not be contained

by anything material. It is easy to

see how the parts of physical, shaped

things fit with the parts of a physical,

shaped sense organ: the image of

the wall that I see is stretched over

the lens of my eye, each of its parts

corresponding to a part of the lens.

But the mind is not a sense organ;

what it grasps are definitions, such

as “Man is a rational, mortal animal”.

The parts of this phrase need to be

grasped at once, together. The mind

therefore cannot be in any way like

or part of the body.

The immortal soul

Avicenna goes on to draw the

conclusion that the mind is not

destroyed when the body dies, and

that it is immortal. This did not

help to make his thinking more

palatable to orthodox Muslims, who

believe that the whole person, body

and mind, is resurrected and enjoys

the afterlife. Consequently, Avicenna

was attacked in the 12th century

by the great Islamic theologian

al-Ghazâlî, who called him a heretic