Quotes from book
On the Soul

Name: On the Soul
Author: Aristotle

Aristotle Original title Περὶ Ψυχῆς

On the Soul is a major treatise written by Aristotle c. 350 BC. Although its topic is the soul, it is not about spirituality but rather a work in what might best be described as biopsychology, a description of the subject of psychology within a biological framework. His discussion centres on the kinds of souls possessed by different kinds of living things, distinguished by their different operations. Thus plants have the capacity for nourishment and reproduction, the minimum that must be possessed by any kind of living organism. Lower animals have, in addition, the powers of sense-perception and self-motion . Humans have all these as well as intellect.

“Sound is the motion of that which is able to be moved, after the manner in which those things are moved, that rebound from smooth bodies, when any one strikes them. Not every thing… sounds… but it is necessary, that the body which is struck should be equable, that the air may collectively rebound, and be shaken. The differences, however, of bodies which sound, are manifested in the sound, which is in energy; for, as colours are not perceived without light, so neither are the sharp and the flat perceived without sound. But these things are asserted metaphorically, from those which pertain to the touch; for the sharp moves the sense much in a short time, but the flat a little in a long time. The sharp, therefore, is not rapid, and the flat slow; but such a motion is produced of the one, on account of celerity, and of the other on account of slowness, that, also, which is perceived in the touch, appears to be analogous to the acute and obtuse, for the acute, as it were, stings; but the obtuse, as it were, impels: because the one moves in a short, but the other in a long time. Hence it happens that the one is swift but the other slow. Let it therefore be thus determined concerning sound.”

Aristotle book On the Soul

Book II : On the soul; In: Aristotle (1808). Works, Vol. 4. p. 62 (412a-424b)
De Anima