cycle could be fully accounted for, the account would neces-
sarily be inaccurate for cycles that were the outgrowth of earlier
or of later conditions. Nor are all the differences between the
successive cycles of one country and between the contemporary
cycles of several countries minor. Even such an elementary
matter as the order in which the phases of a business cycle suc-
ceed one another is not invariable. A revival of business ac-
tivity does not always develop into prosperity--sometimes it
relapses into depression. Such deviations from the usual course
of events occurred in the United States in 1892, 1895, and 1910.
A situation of intense strain, presenting the phenomena of
crises, sometimes occurs in a period of depression, instead of
following a period of prosperity; for example, the American
stringency of 1896. It is needless to elaborate, however, for the
points of difference between any two periods of prosperity, of
crisis, or of depression are scarcely less numerous than the
points of similarity. Every business cycle, strictly speaking, is
a unique series of events and has a unique explanation, because
it is the outgrowth of a preceding series of events, likewise
unique. ²

The theory of business cycles, however, need not be given
up in despair because it cannot satisfy ideal requirements. The
purposes scientific theory serves are met by explanations that
stop far short of radical thoroughness. Much would be gained
for the conduct of individual affairs and the guidance of legis-
lation could we single out from the maze of sequences among
business phenomena a few that are substantially uniform. For,
with a degree of confidence that depends upon the regularity
with which they recur, these sequences could be used as guides

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