On Sense And The Sensible   

temple, so inflicted as to sever the passages of [i.e. inward from]

the eye, feel a sudden onset of darkness, as if a lamp had gone out;

because what is called the pupil, i.e. the translucent, which is a

sort of inner lamp, is then cut off [from its connexion with the

soul].

Hence, if the facts be at all as here stated, it is clear that- if

one should explain the nature of the sensory organs in this way,

i.e. by correlating each of them with one of the four elements,- we

must conceive that the part of the eye immediately concerned in vision

consists of water, that the part immediately concerned in the

perception of sound consists of air, and that the sense of smell

consists of fire. (I say the sense of smell, not the organ.) For the

organ of smell is only potentially that which the sense of smell, as

realized, is actually; since the object of sense is what causes the

actualization of each sense, so that it (the sense) must (at the

instant of actualization) be (actually) that which before (the

moment of actualization) it was potentially. Now, odour is a

smoke-like evaporation, and smoke-like evaporation arises from fire.

This also helps us to understand why the olfactory organ has its

proper seat in the environment of the brain, for cold matter is

potentially hot. In the same way must the genesis of the eye be

explained. Its structure is an offshoot from the brain, because the

latter is the moistest and coldest of all the bodily parts.

The organ of touch proper consists of earth, and the faculty of

taste is a particular form of touch. This explains why the sensory

organ of both touch and taste is closely related to the heart. For the

heart as being the hottest of all the bodily parts, is the

counterpoise of the brain.

This then is the way in which the characteristics of the bodily

organs of sense must be determined.

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