Sentiments concerning nature with which philosophers were delighted
Book I.
Book II.
Book III.
Book IV.
Book V
Thales first pronounced that the soul is that being which is in a perpetual motion, or that whose motion proceeds from itself. Pythagoras, that it is a number moving itself; he takes a number to be the same thing with a mind. Plato, that it is an intellectual substance moving itself, and that motion is in a numerical harmony. Aristotle, that it is the first actuality [Greek ommitted] of a natural organical body which has life potentially; and this actuality must be understood to be the same thing with energy or operation. Dicaearchus, that it is the harmony of the four elements. Asclepiades the physician, that it is the concurrent exercitation of the senses.