948 The American Naturalist. [October, 
PSYCHOLOGY.’ 
Will and Reason in Animals.—One of the greatest needs of 
psychology is a suitable technical terminology. In most of the other 
sciences, the words used have a constant meaning, and one feels reason- 
ably sure of understanding what the author wishes to say. In psy- 
chology there are few terms in use that are not ambiguous. The psy- 
chologist has adopted the phraseology of current speech, and too often, 
in endeavoring to free it of its ambiguity, he forgets that that very 
ambiguity bears witness to a complexity in the matter to be described 
which should not be arbitrarily simplified. 
Especially is this found true when we endeavor to interpret the 
mental processes of the lower animals in terms of our own. We are 
ourselves “conscious,” we “judge,” “reason,” “ will,” and we ask 
whether the lower forms of life are “ conscious,” whether they can 
“judge,” “reason,” “will.” Such questions are vain unless we know 
precisely what mental processes we designate ourselves when we use 
the words. Yet, in most current discussions, it is apparently taken for 
granted that these words have a meaning; that the writer not only 
understands their meaning himself, but is assured that his readers will 
take them in the same sense. Even in the few cases where some seri- 
ous attempt is made to exhibit the exact sense of the terms used, the 
writer proceeds upon the assumption that they have but one legitimate 
sense, and that that is the sense in which he uses them. 
But, in fact, no words in common use have any precise meaning, 
and if this is true of all, it is doubly true of those which express the 
results of crude introspection, performed, for the most part, with prac- 
tical ends in view only. Such are most of our psychological terms. 
While the processes which are designated by any one always have 
some inner bond of similarity, that bond may be, from the point of view 
of the scientific psychologist, s Denai slight importance in view of 
the variations to be found with 
Let us, for example, examine some of the words used of conduct, 
The reflex and instinctive are commonly contrasted with the voluntary, 
and the impulsive are contrasted with the rational. The reflex, in- 
stinctive and impulsive are regarded as “ lower types,” since we share 
them with the lower animals; the voluntary and rational are the 
1 This department is edited by Dr. Wm. Romaine Newbold, University of Penn- 
sylvania. 
