On the hypothesis that the soul remains within herself, while making
use of the light (emanated from the eye) as a rod to reach the visible
object, a very sharp perception would be caused by the resistance
experienced by the light in its tension[172] and sense-color. In
so far as it is color, the light itself would possess the property
of reflecting light. In this case, the contact would take place by
a medium. But already before this the light has reached the object
without any medium; so that the later contact operated by a medium
would produce cognition by a sort of memory or reasoning--which is not
the case.