These substances, existing successively and transmitting their consciousness from one to another, would be something distinct from the act of consciousness, or they would not. If distinct, we must admit a subject of the consciousness, which in itself, and as subject, does not come under the sensible intuition; and consequently we may argue _ad hominem_, and retort Kant's objection against himself. If these transitory substances are only the act of the consciousness, when the act ceases, nothing remains of the substances, and therefore, there is nothing transmissible. Transmission supposes something which may be transmitted; if, then, the act of consciousness is transmitted, it must be something permanent in itself, in the midst of the succession of the substances; and this is a very strange conclusion to which the German philosopher is brought by his theory of transmission. All psychologists had said that the substance of the soul is permanent, and its phenomena transitory; now, on the contrary, we find that the transitory is the substance, and that which is permanent is the phenomenon, or the act of consciousness which is transmitted. 66. Perhaps it may be answered that by transmission is not meant the communication of any thing constant, but merely the succession of phenomena united by any tie among themselves. Thus, supposing the instants A, B, C, D, the acts of consciousness, _a_, _b_, _c_, _d_, corresponding to them, will not be strictly identical in number, but successive, and connected. But this reply, which avoids the necessity of admitting the permanence of the act of consciousness, explains nothing, and makes it incomprehensible, how, at the instant D, for example, there can be consciousness of the acts _c_, _b_, _a_, which there is an irresistible inclination to believe have at bottom something numerically identical. When _d_ exists there is no longer any thing of _c_ left; there is no substance remaining, because, by the supposition there either is no such substance, or it is something transitory; there is no act of consciousness remaining, because _a_ is numerically distinct from _c_, and besides, we have seen that the permanence of the phenomena cannot be admitted. Therefore it is absolutely impossible to explain or to comprehend how there can be in the act _a_ the representation of _c_. 67. To say that the phenomena are united by any tie whatever is to elude the difficulty by a foolish play upon words. What is the meaning, in this case, of uniting, of a tie? They are metaphors which if they mean any thing must express the permanence of some _thing_ amid the variety of the phenomena; the tie, the bond, must extend to the various things which it connects and unites: therefore it must be _common_ to them all; and this something, whatever it be, which remains constant in variety, we call substance.