Kant says, Time cannot be perceived; therefore no succession of representations can be empirically perceived as objective: _i.e._ can be distinguished as changes in phenomena from the changes of mere subjective representations. The causal law, being a rule according to which states follow one another, is the only means by which the objectivity of a change can be known. Now, the result of his assertion would be, that no succession in Time could be perceived by us as objective, excepting that of cause and effect, and that every other succession of phenomena we perceive, would only be determined so, and not otherwise, by our own will. In contradiction to all this I must adduce the fact, that it is quite possible for phenomena to _follow upon_ one another without _following from_ one another. Nor is the law of causality by any means prejudiced by this; for it remains certain that each change is the effect of another change, this being firmly established _à priori_; only each change not only follows upon the single one which is its cause, but upon all the other changes which occur simultaneously with that cause, and with which that cause stands in no causal connection whatever. It is not perceived by me exactly in the regular order of causal succession, but in quite a different order, which is, however, no less objective on that account, and which differs widely from any subjective succession depending on my caprice, such as, for instance, the pictures of my imagination. The succession, in Time, of events which stand in no causal connection with each other is precisely what we call _contingency_.[100] Just as I am leaving my house, a tile happens to fall from the roof which strikes me; now, there is no causal connection whatever between my going out and the falling of the tile; yet the order of their succession--that is, that my going out preceded the falling of the tile--is objectively determined in my apprehension, not subjectively by my will, by which that order would otherwise have most likely been inverted. The order in which tones follow each other in a musical composition is likewise objectively determined, not subjectively by me, the listener; yet who would think of asserting that musical tones follow one another according to the law of cause and effect? Even the succession of day and night is undoubtedly known to us as an objective one, but we as certainly do not look upon them as causes and effects of one another; and as to their common cause, the whole world was in error till Copernicus came; yet the correct knowledge of their succession was not in the least disturbed by that error. Hume's hypothesis, by the way, also finds its refutation through this; since the following of day and night upon each other--the most ancient of all successions and the one least liable to exception--has never yet misled anyone into taking them for cause and effect of each other.