On Sense And The Sensible   

A gleam of fire blazing through the stormy night,

Adjusting thereto, to screen it from all sorts of winds,

transparent sides,

Which scatter the breath of the winds as they blow,

While, out through them leaping, the fire,

i.e. all the more subtile part of this,

Shines along his threshold old incessant beams:

So [Divine love] embedded the round "lens", [viz.]

the primaeval fire fenced within the membranes,

In [its own] delicate tissues;

And these fended off the deep surrounding flood,

While leaping forth the fire, i.e. all its more subtile part-.



Sometimes he accounts for vision thus, but at other times he

explains it by emanations from the visible objects.

Democritus, on the other hand, is right in his opinion that the

eye is of water; not, however, when he goes on to explain seeing as

mere mirroring. The mirroring that takes place in an eye is due to the

fact that the eye is smooth, and it really has its seat not in the eye

which is seen, but in that which sees. For the case is merely one of

reflexion. But it would seem that even in his time there was no

scientific knowledge of the general subject of the formation of images

and the phenomena of reflexion. It is strange too, that it never

occurred to him to ask why, if his theory be true, the eye alone sees,

while none of the other things in which images are reflected do so.

True, then, the visual organ proper is composed of water, yet vision

appertains to it not because it is so composed, but because it is

translucent- a property common alike to water and to air. But water

is more easily confined and more easily condensed than air;

wherefore it is that the pupil, i.e. the eye proper, consists of

water. That it does so is proved by facts of actual experience. The

substance which flows from eyes when decomposing is seen to be