individuals could be repeated, the same circumstances could not a second time produce the same effects. Men of different characters are affected in very different ways by the same influences, and the characters of any particular generation of men are always very different from those of every preceding generation. Let it be supposed, for the sake of argument, that the French of the present day could be placed in precisely the same social condition in which their fathers were towards the close of the last century; still they would act very differently from their fathers. Nay, even though they should, with one single exception, have inherited the dispositions of their fathers, the difference of character in one single individual might suffice to give an entirely new turn to the course of events. If every other antecedent of the first French Revolution were again present, still there might be no second revolution, provided only that, instead of another Louis the Sixteenth, a Leopold of Belgium, or a Frederick the Great were king.[28] With the last mentioned on the throne, there would assuredly be no repetition of that vacillation of purpose which rocked the cradle and fostered the growth of popular fury till it culminated in a Reign of Terror. Since, then, there cannot be either a repetition of the same circumstances to act upon men, or a reproduction of the same sort of men to be acted upon by circumstances, human conduct can never exhibit a repetition of the same phenomena; experience of the past can never, in social or political affairs, furnish a formula for predictions as to the future. Accordingly Mr. Mill, in common with Mr. Stephen, disclaims the idea of positive, and pleads only for conditional, predictions. But the very term 'conditional predictions' involves a contradiction, since it is obviously impossible to see beforehand what perhaps may never come to pass. What is meant by the phrase is really nothing more than conjectures; and conjectures, however ingenious and reasonable, cannot be admitted within the pale of science. They cannot be accepted as fruits of a tree which has by the quality of its fruits proved its right to be entitled the Science of History.