68. The mere succession of the phenomena or acts of consciousness is not sufficient to transmit the belief of the numerical identity; if it were, all men would be conscious of the previous acts of others. Let _a_, _b_, be two successive acts of consciousness: if, in order that the act _b_, which is numerically distinct from _a_, may represent the numerical identity of consciousness, it is sufficient that _b_ should succeed _a_; since this succession is met with in the acts of consciousness of different men, it must follow that all men have consciousness of all the acts of the others. _Risum tematis?_ And yet this conclusion is absolutely necessary: it cannot be avoided by saying that there is a form of the internal sense, and that the succession takes place in each man in his respective internal sense, and that therefore the succession of the internal phenomena of one is in a different time, in a different form from what it is in another. The words, _respective_ internal sense, internal form of _each_ man, have a meaning, if we admit something permanent in our interior; but if there is nothing but successive phenomena, the word _respective_ is absurd, because there can be no respective internal sense if there is nothing to which it can refer. Suppose the man M, and the man N be merely a succession of phenomena, and in _each_ one there is only a mere succession: there is the same reason why the phenomena of N should be connected with each other as with those of M. Therefore, if there is a community of consciousness in the phenomena of M, without any other sufficient reason than the mere succession, this community should be found in all the phenomena, because they all have the same sufficient reason.