REVIEWS OF RECENT LITERATURE. 59 
upon an interpretation of animal nature through the analogy of our 
own. “We make the world of animal life about us a reflection of 
ourselves; we spontaneously implant in the bird and the squirrel 
qualities that are our own. ‘They interest us in proportion as they 
seem to embody the same thoughts and feelings as ourselves.” But 
this is not the only, nor, indeed, the most important aspect of the 
study. The science of physiology has grown up almost wholly 
through experiments performed upon the lower animals; we must 
apply the same method to psychology; to understand adequately 
the processes of the human mind, we must study the nature and 
development of more primitive forms of life. A few words will indi- 
cate the relations in which the results of animal psychology have an 
important bearing upon the questions of human psychology. 
It is scarcely a generation since the first psychological laboratories 
were founded; but in the brief years which have intervened between 
that time and this there have grown up dozens of such experimental 
stations, in which skilled observers carry on patient and detailed 
study of the phenomena of our mental life. 
One of the chief difficulties which these experimental psychologists 
have to solve is the production of a naive attitude in the subject of 
the experiment. The mature human being is a mass of ingrained 
conventions which very greatly transform his original impulses. The 
primary reaction, the elementary motif, the native trend of desire, the 
unqualified conviction, are overlaid and. disguised by a thousand 
modifying considerations and restraints imposed upon him by the 
very form of his social life. He clothes himself in inhibitions as: in 
a garment, and anything which will aid in stripping off this fabric of 
secondary impulses, and secure for the student a direct observation 
of the naked tendency, is to be welcomed for the light it throws upon 
the complex object of his study. 
To simplify the conditions under which the mental process takes 
place, and at the same time to maintain its typical character, is the 
problem of the psychological investigator ; and to fulfill these require- 
ments he goes far afield from the study of the normal adult subject 
and calls many diverse observers to his aid. 
The pursuit of these simpler conditions has gone in two main 
directions : first, into the province of pathology, where abnormal 
variations have presented certain elements so heightened in value 
that the network of ordinary inhibitions has been torn away and the 
exaggerated impulses can be observed with a directness unattainable 
in the normal individual ; and, second, into the realm of more primi- 
