by the writer in 1898, and first published in brief outline in an article of this Journal 1 in May, 1899. The purpose of this paper is merely to expand and restate the theory there presented. It is not an attempt, however, to give the theory anything more than a tentative form; its details must necessarily be left to be worked out through the further development of psychology and sociology. Moreover, it is not claimed that this theory of revo- lutions is anything absolutely new; foreshadowings of it are to be found in many historical and sociological writers. 2 The essence of the theory is this : that revolutions are disturbances in the social order due to the sudden breakdown of social habits under conditions which make difficult the reconstruction of those habits, that is, the formation of a new social order. In other words, revolutions arise through certain interferences or dis- turbances in the normal process of the readjustment of social habits.
The merit which is claimed for this theory is that it is in harmony with the new psychology and attempts to explain revo- lutions in terms of habit and adaptation. Habit and adaptation have their social consequences, not less than their individual men- tal consequences. The institutions and customs of society are but social expressions of habit; while the normal changes in the social order may be looked upon as social adaptations. Habit and adaptation are, therefore, fundamental categories for the interpretation of the social life-process not less than of the indi- vidual life-process; and the theory of revolutions here presented attempts to bring their phenomena within these categories.
Normally social habits are continually changing; old habits are gradually replaced by new ones as the life-conditions change. Normally the breakdown of a social habit is so gradual that by the time the old habit disappears a new habit has been con- structed to take its place. Thus the process of social change, of continuous readjustment in society, goes on under normal condi-
1 American Journal of Sociology, Vol. IV, pp. 817, 818.
2 Among historical writers Carlyle might be mentioned (cf. his French Revo- lution, Vol. I, p. 38) ; among sociologists, Ward especially has approximated the above views (cf. his Pure Sociology, pp. 222-31).
