a certain regular succession; a certain law of association seems to govern their movements, as is seen in the rapid motions of the pianist, the flute player, the type distributor, and in many similar cases; and so long as the regular succession, and accustomed order of movement, is undisturbed, the process goes on with little or no interference of the intellectual principle. In such cases the act can hardly be said to involve mental activity. _A further Question._--But aside from this, even admitting that the acts under consideration are such as to involve mental activity, what evidence is there, it may still be asked, that there was at the moment no consciousness of that activity? That there was _subsequently_ no consciousness of it, does not make it certain that there was none at the time. The subsequent consciousness of an act is neither more nor less than memory, and is not properly consciousness at all. Consciousness takes cognizance, properly speaking, only of the present, not of the past. The absence of subsequent consciousness is simply absence of memory, and this may be accounted for in other ways than by supposing a total absence of consciousness in the first instance. Whatever mental activity was really exerted by the short-hand reporter in the case referred to, he was, doubtless, conscious of exerting at the time, but it may have been so slight, and the mind so little impressed by it, in the state of physical weariness and prostration, that it was not remembered a moment afterward. We remember not every thing that occurs, but only that to which we attend, and which makes some impression upon us. _The true Explanation._--In the other cases referred to, the explanation now given is still more evidently the true one. What is called an absence of consciousness is simply an absence of attention at the time, and consequently of memory afterward. The person who is reading aloud, in the case supposed, is mentally occupied with something else than the sentiments of the author, is not attending, in a word, to what he is reading, and hence does not, a moment after, remember what it was that he read. So of the striking of the clock. The sound fell upon the ear, the auditory nerve performed its office, the usual change, whatever it may be, was produced in the brain, but the process of hearing went no further; either no mental activity was awakened by that sound, or, if any, but the slightest, for the mind was otherwise occupied, in a word, did not attend to the summons of the messenger that waited at the portal, and hence there was no subsequent remembrance of the message, or at most a vague impression that something of the kind was heard. On the whole, it does not appear from the cases cited, that mental activity is ever, at the moment of its exertion, unaccompanied with consciousness.