1. What is the cause that when distant visible objects seem smaller,
and that, though separated by a great space, they seem to be close to
each other, while if close, we see them in their true size, and their
true distance? The cause of objects seeming smaller at a distance might
be that light needs to be focussed near the eye, and to be accommodated
to the size of the pupils[50]; that the greater the distance of the
matter of the visible object, the more does its form seem to separate
from it during its transit to the eyes; and that, as there is a form
of quantity as well as of quality, it is the reason (or, form) of the
latter which alone reaches the eye. On the other hand, (Epicurus)
thinks that we feel magnitude only by the passage and the successive
introduction of its parts, one by one; and that, consequently,
magnitude must be brought within our reach, and near us, for us to
determine its quantity.