There is no exact method of measuring the intensity of all psychological
processes, but—as in the case of forming concepts of colors—conceptualization
does not require the knowledge of exact measurements. Degrees of intensity can
be and are measured approximately, on a comparative scale. For instance, the
intensity of the emotion of joy in response to certain facts varies according
to the importance of these facts in one’s hierarchy of values; it varies in
such cases as buying a new suit, or getting a raise in pay, or marrying the
person one loves. The intensity of a process of thought and of the intellectual
effort required varies according to the scope of its content; it varies when
one grasps the concept “table” or the concept “justice,” when one grasps that 2
+ 2 = 4 or that e = mc2.