36 
LE CONTE. 
we see the next change take place— i. e., the emergence of 
the psychic out of the vital. In the germ-cell, in the egg, 
and even in the earlier stages of the embryo, there is no dis¬ 
tinctive animal life— i. e., no consciousness nor volition nor 
response of any kind to stimulus. At a certain stage, dis¬ 
tinctive animal or psychic life appears. We call it quick¬ 
ening. Materials for psychology are now present for the first 
time. In man alone, and that only sometime after physical 
birth, we see the last change. The new-born child is pos¬ 
sessed of animal life onty. The emergence into self-con¬ 
sciousness—a change so wonderful that it may well be called 
the birth of spirit—takes place only at the age of two or three 
years. Now, for the first time, we have phenomena which 
are the subject-matter of philosophy. 
Now all these forces, as we have shown, operate on sepa¬ 
rate planes without gradations. When appropriate condi¬ 
tions are present, force or energy changes from one form to 
another at once. The gaps separating these planes become 
greater and greater as we rise. The scale of forces, like the 
scale of chemical substances, may be likened to a ladder, the 
rounds of which grow farther and farther apart as we rise. 
By far the greatest gap between these successive planes or 
rounds is the last, or that between the psychic and the spir¬ 
itual plane; but, although thus distinct, they are not unre¬ 
lated. They are related to one another, as already seen, in 
their origin. They continue to be always related by mutual 
dependence. Each higher force as it rises dominates all 
below and uses them for its own higher purposes, but is 
itself underlain and conditioned by the lower. The sciences 
of which they form the subject-matter are therefore similarly 
related. As the physical underlies and conditions chemical 
phenomena, and therefore the accomplished chemist must 
understand physics; as the chemical underlies and condi¬ 
tions life-phenomena, and therefore the physiologist must 
understand chemistry ; as vital forces underlie and condi¬ 
tion psychical phenomena, and therefore the psychologist 
must understand physiology, so also psychical forces under- 
