That the remembrance is produced in no other way, {327} is proved by a decisive experiment. For, after a passage has been committed to memory in the most perfect manner, if the learner attempts to repeat it in any other order than that, according to which the association was formed, he will fail. A man who has been accustomed to repeat the Lord's Prayer, for example, from his infancy, will, if he has never tried it, find the impossibility of repeating it backwards, small as the number is of the words of which it consists. That words alone, without ideas, suggest one another in a train, is proved by our power of repeating a number of words of an unknown language.[90] And, it is worth observing, that the power of arithmetical computation is dependent upon the same process. Thus, for example, when a child learns the multiplication table, and says, 11 times 11 is 121, or 12 times 12 is 144, he annexes no ideas to those words; but, by force of repetition, the expression 12 times 12 instantly calls up the expression 144, or 11 times 11 the expression 121, and so upwards from twice 2, with which he begins. In illustrating the mode in which repetition makes association more and more easy, I used the process of arithmetical addition as a striking example. Persons little accustomed to the process perform it with great difficulty; persons {328} much accustomed to it, with astonishing facility. In men of the first class, the association is imperfectly formed, and the several antecedent expressions slowly suggest the proper consequent ones; in those of the latter class the association is very perfectly formed, and the expressions suggest one another with the greatest expedition and ease. [Editor's footnote 90: There is here a lapse, of mere expression. The meaning is not that words suggest one another without ideas; words do not suggest words, but the ideas of words. The author intended to say that words, or the ideas of them, often suggest the ideas of other words (forming a series) without suggesting along with them any ideas of the things which those words signify.--_Ed._] Thus far we have proceeded with facility. In Memory there are ideas, and those ideas both rise up singly, and are connected in trains by association. The same occurs in Imagination. Imagination consists of ideas, both suggested singly, and connected in trains, by association. This is the whole account of Imagination. But Memory is not the same with Imagination. We all know, when we say, we imagine a thing, that we have not the same meaning, as when we say, we remember it. Memory, therefore, has in it all that Imagination has; but it must also have something more. We are now, then, to inquire what that additional something is.