There are two cases of Memory. One is, when we remember sensations. The other is, when we remember ideas. The first is, when we remember what we have seen, felt, heard, tasted, or smelt. The second is, when we remember what we have thought, without the intervention of the senses. I remember to have seen and heard George III, when making a speech at the opening of his Parliament. This is a case of sensation. I remember my conceptions of the Emperor Napoleon and his audience, when I read the account of his first address to the French Chambers. This is a case of ideas. {329} We shall consider the case of sensations first. What is it to remember any thing I have seen? First, there is the idea of it; and that idea brought into existence by association. But, in Memory, there is not only the idea of the thing remembered; there is also the idea of my having seen it. Now these two, 1, the idea of the thing, 2, the idea of my having seen it, combined, make up, it will not be doubted, the whole of that state of consciousness which we call memory.[91] [Editor's footnote 91: The doctrine which the author thinks "will not be doubted" is more than doubted by most people, and in my judgment rightly. To complete the memory of seeing the thing, I must have not only the idea of the thing, and the idea of my having seen it, but the belief of my having seen it; and even this is not always enough; for I may believe on the authority of others that I have seen a thing which I have no remembrance of seeing.--_Ed._] But what is it we are to understand by what I have called "the idea of my having seen the object?" This is a very complex idea; and, in expounding, clearly, to the comprehension of persons, not familiar with these solutions, the import and force of a very complex idea, lies all the difficulty of the case. It will be necessary for such persons to call to mind the illustrations they have already contemplated of the remarkable case of association, in which a long train of ideas is called up so rapidly as to appear but one idea; and also the other remarkable case, in which one idea is so strongly associated with another, that it is out of our power to separate them. Thus, when we use the word battle, the mind runs over the {330} train of countless acts, from the beginning of that operation to the end; and it does this so rapidly, that the ideas are all clustered into one, which it calls a battle. In like manner, it clusters a series of battles, and all the intermediate operations, into one idea, and calls it a campaign; also several campaigns into one idea, and calls it a war. Of the same nature is the compound idea, which we denote by the word year; and the still more compound idea, which we denote by the word century. The mind runs over a long train of ideas, and combines them so closely together, that they assume the appearance of a single idea; to which, in the one case, we assign the name year, in the other, the name century.