gIo The American Naturalist. [October, 
reason must be gained from this research. It is well known 
that three distinct views may be taken of the source of this im- 
portant faculty. These positions are the two extremes of realism 
and idealism, and the intermediate one maintained by Kant. 
According to Locke and the experiential school reason is a pro- 
duct of sense-perception or experience, and is æ posteriori. Ac- 
cording to Berkeley, Hegel, and the idealists, this faculty is priort 
or intuitive, and creates the material world in its own likeness. 
Of this likeness sense-perception is the expression. According 
to Kant, sense-perception of a real universe is the material of 
thought, but it can only be comprehended through the necessary 
logical form of thought, which’therefore presents a real material 
world to us in this form, but not as it is in itself. The relation 
which the evolution of mind has to this question will be consid- 
ered in another essay. 
Conception.—While perception and emotion are very generally 
granted to animals, it has been often denied that they are capable 
of conception or generalization. The formation of a concept is a 
result of classification, and the general idea which is a concept, is 
not an object, but a mental picture of several objects or parts of 
objects in combination. Concepts are of various grades of gen- 
erality, as may be exhibited in the following table: 
Energy. 3 
Se _ 
Color. Other kinds of Energy. 2 
y d S 
Red or redness. Yellow or yellowness. : I 
e MS 
r Li 
Red thing No.1. R.t. No.2. R.t. No. 3. Yellow thing No. z. Y. t. No. 2. Y.t No.3. 
In the above analysis three grades of generalization are repre- 
sented ; all derived from the individual objects enumerated in the 
bottom line. Each one requires successively greater mental 
grasp, and in the case of the highest generalization, the especial 
knowledge attained only by the scientific man. But the first or 
lowest grade of generalization is clearly within the scope of the 
animal mind. Thus the bull attacks a red object without ascer- 
taining especially whether it is blood or a red cloth; he sees only 
