The two great difficulties which adhere to the theory of Materialism, and which must ever prove insurmountable, are these: first, to account for the power of thinking by means of material atoms, which are individually destitute of it; and secondly, to account for the unity and continuity of human consciousness by means of material atoms which are constantly undergoing flux and mutation. For the first end, recourse has been had to the theory which ascribes the power of thinking, not to the particles of matter, but to their order, arrangement, or organization; and for the second, the continuous sense of personal identity is supposed to be sufficiently accounted for by supposing that, as the particles which compose the brain are changed, the retiring atoms leave their share of the general consciousness as a legacy to their successors. And both these expedients for surmounting the difficulty are exquisitely caricatured in the "Memoirs of Martinus Scriblerus," in a chapter which is justly described as "an inimitable ridicule on Collins' argument against Clarke, to prove the soul only a quality." The Society of Freethinkers, addressing Martinus, propose to send him an answer to the ill-grounded sophisms of their opponents, and likewise "an easy mechanical explanation of perception or thinking."--"One of their chief arguments," say they, "is that self-consciousness cannot inhere in any system of matter, because all matter is made up of several distinct beings which never can make up one individual thinking being. This is easily answered by a familiar instance. In every _jack_ there is a _meat-roasting_ quality, which neither resides in the fly, nor in the weight, nor in any particular wheel, of the jack, but is the result of the whole composition.... And as the general quality of meat-roasting, with its several modifications, does not inhere in any one part of the jack, so neither does consciousness, with its several modes of sensation, intellection, volition, &c., inhere in any one, but is the result from the mechanical composition of the whole animal." And then, in regard to the _second_ difficulty: "The parts," say they, "of an animal body are perpetually changed, ... from whence it will follow that the idea of individual consciousness must be constantly translated from one particle of matter to another.... We answer, this is only a fallacy of the imagination. They make a great noise about this _individuality_, how a man is conscious to himself that he is the same individual he was twenty years ago, notwithstanding the flux state of the particles of matter that compose his body. We think this is capable of a very plain answer, and may be easily illustrated by a familiar example. Sir John Cutler had a pair of black worsted stockings, which his maid darned so often with silk, that they became at last a pair of silk stockings. Now, supposing those stockings of Sir John's endued with some degree of