This gives us, too, the clue to the distinction between {296}
the inorganic and the organic. If inorganic matter is what
has its end outside itself, organic matter will be what has
its end within itself. This is the essential character of an
organism, that its end is internal to it. It is an inward
self-developing principle. Its function, therefore, can only
be the actualisation, the self-realization of this inward end.
Whereas, therefore, inorganic matter has no activity ex-
cept spatial movement, organic matter has for its activity
growth, and this growth is not the mere mechanical addi-
tion of extraneous matter, as we add a pound of tea to a
pound of tea. It is true growth from within. It is the mak-
ing outward of what is inward. It is the making explicit of
what is implicit. It is the making actual of what is potential
in the embryo organism.
The lowest in the scale of being is thus inorganic matter,
and above it comes organic matter, in which the principle
of form becomes real and definite as the inward organiza-
tion of the thing. This inward organization is the life, or
what we call the soul, of the organism. Even the human
soul is nothing but the organization of the body. It stands
to the body in the relation of form to matter. With or-
ganism, then, we reach the idea of living soul. But this
living soul will itself have lower and higher grades of be-
ing, the higher being a higher realization of the principle of
form. As the essential of organism is self-realization, this
will express itself first as self-preservation. Self-preservation
means first the preservation of the individual, and this gives
the function of nutrition. Secondly, it means preservation
of the species, and this gives the function of propagation.
The lowest grade in the organic kingdom will, therefore,
be {297} those organisms whose sole functions are to nour-
ish themselves, grow, and propagate their kind. These are
plants. And we may sum up this by saying that plants pos-
sess the nutritive soul. Aristotle intended to write a treatise
upon plants, which intention, however, he never carried out.
All that we have from him on plants is scattered references
in his other books. Had the promised treatise been forth-
coming, we cannot doubt what its plan would have been.
Aristotle would have shown, as he did in the case of ani-
mals, that there are higher and lower grades of organism
within the plant kingdom, and he would have attempted to
trace the development in detail through all the then known
species of plants.Next above plants in the scale of being come animals. Since
the higher always contains the lower, but exhibits a further
realization of form peculiar to itself, animals share with
plants the functions of nutrition and propagation. What is
peculiar to them, the point in which they rise above plants,
is the possession of sensation. Sense-perception is therefore
the special function of animals, and they possess, therefore,
the nutritive and the sensitive souls. With sensation come
pleasure and pain, for pleasure is a pleasant sensation, and
pain the opposite. Hence arises the impulse to seek the
pleasant and avoid the painful. This can only be achieved
by the power of movement. Most animals, accordingly, have
the power of locomotion, which is not possessed by plants,
because they do not require it, since they are not sensitive
to pleasure and pain. In his books upon animals Aristotle
attempts to carry out the principle of development in detail,