e soul of man is divided into three parts: into
intuition and reason and mind, and that the first and last divisions are
found also in other animals, but that the middle one, reason, is only
found in man. And that the chief abode of the soul is in those parts
of the body which are between the heart and the brain. And that that
portion of it which is in the heart is the mind; but that deliberation
and reason reside in the brain.

"Moreover, that the senses are drops from them; and that the reasoning
sense is immortal, but the others are mortal. And that the soul is
nourished by the blood; and that reasons are the winds of the soul.
That it is invisible, and so are its reasons, since the aether itself is
invisible. That the links of the soul are the veins and the arteries
and the nerves. But that when it is vigorous, and is by itself in a
quiescent state, then its links are words and actions. That when it
is cast forth upon the earth it wanders about, resembling the body.
Moreover, that Mercury is the steward of the souls, and that on this
account he has the name of Conductor, and Commercial, and Infernal,
since it is he who conducts the souls from their bodies, and from earth
and sea; and that he conducts the pure souls to the highest region, and
that he does not allow the impure ones to approach them, nor to come
near one another, but commits them to be bound in indissoluble fetters
by the Furies. The Pythagoreans also assert that the whole air is full
of souls, and that these are those which are accounted daemons and
heroes. Also, that it is by them that dreams are sent among men, and
also the tokens of disease and health; these last, too, being sent not
only to men, but to sheep also, and other cattle. Also that it is they
who are concerned with purifications and expiations and all kinds of
divination and oracular predictions, and things of that kind."(5)

A brief consideration of this summary of the doctrines of Pythagoras
will show that it at least outlines a most extraordinary variety of
scientific ideas. (1) There is suggested a theory of monads and the
conception of the development from simple to more complex bodies,
passing through the stages of lines, plain figures, and solids to
sensible bodies. (2) The doctrine of the four elements--fire, water,
earth, and air--as the basis of all organisms is put forward. (3)
The idea, not merely of the sphericity of the earth, but an explicit
conception of the antipodes,