{362} But there can be no idea of the future; because, strictly speaking, the future is a nonentity. Of nothing there can be no idea. It is true we can have an idea of that which never existed, and which we do not suppose ever will exist, as of a centaur; but this is a composition of the ideas of things which have existed. We can conceive a sea of milk, because we have seen a sea, and milk; a mountain of gold, because we have seen a mountain, and gold. In the same manner we proceed with what we call the future. The ideas which I have recently enumerated as parts of my belief of to-morrow; the light of day, the throng in the streets, the motion of the tide at London-bridge, are all ideas of the past. The general fact, indeed, is not a matter of dispute. Our idea of the future, and our idea of the past, is the same; with this difference, that it is accompanied with retrospection in the one case, anticipation in the other. What retrospection is, we have already examined. It is Memory. What Anticipation is, we are now to inquire; and to that end it is necessary to recall, distinctly, some important facts which we have already established. The fundamental law of association is, that when two things have been frequently found together, we never perceive or think of the one without thinking of the other. If the visible idea of a rose occurs to me, the idea of its smell occurs along with it; if the idea of the sound of a drum occurs to me, the visible idea of that instrument occurs along with it. Of these habitual conjunctions, there is none with which we are more incessantly occupied, from the {363} first moment of our existence to the last, and in which we are more deeply interested, than that of antecedent and consequent. Of course there is none between the ideas of which the association is more intimate and intense. In fact, our whole lives are but a series of changes; that is, of antecedents and consequents. The conjunction, therefore, is incessant; and, of course, the union of the ideas perfectly inseparable. We can no more have the idea of an event without having the ideas of its antecedent and *its consequents, than we can have the idea and not have it at the same time. It is utterly impossible for me to have the visible idea of a rose, without the idea of its having grown from the ground, which is its antecedent; it is utterly impossible for me to have the idea of it without the ideas of its consistence, its smell, its gravity, and so on, which are its consequents.