man's own breast. If any one should choose to assert that two and two make six, or that the sun is the moon, I can only answer that these ideas as they exist in my mind are totally different. In like manner I am conscious of certain operations in my own mind in comparing two equal lines together essentially different from the perception of the contiguity of their extremities, and I therefore conclude that the ideas of equality and contiguity are not the same.
The second question is whether the idea of contiguity itself is an idea of mere association; that is, whether it is nothing more than the recollection of a compound sensation. If by sensation is to be understood the direct impression of the parts of any outward object on corresponding parts of an extended living substance, by which the general mass is converted from a dead into a living thing, and that this is the only difference that takes place, then I deny that this combination of living atoms, this diffusion of animal sensibility, however exquisite or thrilling to the slightest touch, will ever give the idea of relation of any kind whether of contiguity, coexistence, or any thing else, either immediately at the time or by recollection afterwards. It has been said that to feel is to think, "sentirest penser:" I believe this to be true of the human mind, because the human mind is a thinking principle: it is natural to it to think: it cannot feel without thinking; but this maxim would not be at all true of such a human mind as is described by these philosophers, equally incapable both of thought, and feeling as it exists in us. As this distinction is very difficult to be expressed, I hope I may be allowed to express it in the best way that I am able. Suppose a number of animalculæ, as a heap of mites in a rotten cheese, lying as close together as they can stick, (though the
