14 
C. L. Herrick 
conscious act is always a fluctuation of equilibrium, so that all cognitive 
elements are awakened in response to changes rather than invariable 
or monotonous stimuli” (pp. 155-157). 
In the article on Brain in Baldwin’s Dictionary of Philosophy 
and Psychology, Professor Herrick briefly states the theory as 
follows : 
The theory of consciousness which seems best to conform to the con- 
ditions of brain structure and its observed unity is that each conscious 
state is an expression of the total equilibrium of the conscious mechan- 
ism, and that intercurrent stimuli are continually shifting the equi- 
librium from one to another class of activities. In other words, the sen- 
sation accompanying a given color presentation is not due to the vibra- 
tions in the visual center in the occipital lobe, but to the state of cortical 
equilibrium or the equation of cortical excitement when that color stim- 
ulus predominates. Previous vestigial excitements and coordinations 
with the data from other cortical centers all enter into the conscious 
presentation. As the wave of excitation passes from the visual center 
to other parts, the proportional participation of other centers increases, 
producing a composite containing more distantly related elements (p. 
135). 
The widely current belief in the anatomical separateness of 
the neurones entering into this neural equilibrium accords well 
with the theory and in fact either such an anatomical or some sort 
of a physiological barrier to the free discharge of nervous impulses 
is essential for the explanation of some of the facts. The theories 
of retraction of the neurone under varying functional conditions 
are particularly attractive in this connection, the education of 
the nervous system also being conceived as involving the develop- 
ment of new functional pathways as new associations are acquired 
and the short-circuiting of the old ones as activities become 
mechanized. Many of the peculiarities of inhibition or resist- 
ance to nerve stimuli may be explained as the result of contrac- 
tions of the functional processes of the nerve cells. 
[But much more fruitful in this connection are the more recent 
physiological theories of intemeural resistance, particularly the 
carefully elaborated doctrine of the synapse of Sherrington. — 
Editor.] 
Whether or not the theory of retraction be accepted in its 
present form, it is important as an attempt to state a device for 
breaking and making the organic circuit necessary to conscious- 
