PSYCHOLOGY: W. CRAIG 
687 
Some forms of behavior show all four phases clearly. In other cases 
one or other of the phases is not clearly present. When the bird shows 
appetitive behavior but fails to obtain the appeted stimulus, the appe- 
tite sometimes disappears, due to fatigue or to drainage of energy into 
other channels. But some instinctive appetites are so persistent that 
if they do not attain the normal appeted stimulus they make connection 
with some abnormal stimulus; to this the consummatory reaction takes 
place, the tension of the appetite is relieved, its energy discharged, and 
the organism shows satisfaction. This is 'compensation' in the sense 
in which that word is used in psychiatry. The cycles and phases of 
cycles are multiplied and overlapped in very complex ways. Smaller 
cycles are superposed upon larger ones. The time occupied by each 
varies greatly, from cycles measured in seconds to those that occupy a 
year or even longer. 
The successive phases are not sharply separated. Thus, from the 
last phase of one cycle in a series to the first phase of the succeeding 
cycle, there is often a gradual rise of appetite ; active search for satisfac- 
tion does not commence until a certain intensity of appetite is attained. 
This is what is known in pedagogical literature as 'warming up.' This 
gradual rise of the energy of appetite is followed (Phases II-III, or 
II-IV) by its sudden or gradual discharge. The rise and discharge are 
named by Ellis,^ in the case of the sex instinct, 'tumescence' and 'de- 
tumescence.' They are important phases in the psychology of art, in 
which sphere they are named by Hirn'^ 'enhancement' and 'relief.' The 
discharge (Phase II) is also exemplified in 'catharsis' in art and in 
psychiatry. 
All human behavior runs in cycles which are of the same fundamental 
character as the cycles of avian behavior. These appear in conscious- 
ness as cycles of attention, of feeling, and of valuation. This descrip- 
tion is true not only of our behavior toward objects specifically sought 
by instinct, such as food, mate, and young, but also of our behavior 
toward the objects of our highest and most sophisticated impulses, such, 
for example, as a symphony concert. The entire behavior of the human 
being is, like that of the bird, a vast system of cycles and epicycles, the 
longest cycle extending through life, the shortest being measured in sec- 
onds, each cycle involving the rise and the termination of an appetite. 
This view helps us to understand the laws of attention ; for example, the 
law that attention cannot be held continuously upon a faint, simple 
stimulus. For as soon as such a stimulus is brought to maximum clear- 
ness, which constitutes the consummatory situation, the appetite for it 
is quickly discharged and its cycle comes to an end. This familiar fact 
