than the affirming that a thing never moves in the direction in which it is going, but always out of it; for, if it moves in the same direction, the smallest moment of time, this is not a curve, but a strait line; and if it does not continue to move in the same direction at all, it seems utterly inconceivable that it should make any progress, or move either in a curve or a strait line. Yet any one who, on the strength of the contradiction involved in the ideas of extension, motion, or curve lines, should severally deny or disbelieve any one of them, would be thought to want common sense. I think there are certain facts of the mind which are equally evident and unaccountable. Those who contend that the one are to be admitted, and the other not, because the one are the objects of sense, and the other not, do not deserve any serious answer. It is as much a fact, that I remember having seen the sun yesterday, as that I see it to-day, and both of them are much more certain facts, than that there is any such body as the sun really existing out of the mind.
I will now return to Berkeley, and endeavour to answer his chief objections to the doctrine of abstract ideas. First, then, I conceive that he has himself virtually given up the question, when he allows that the mind may be affected with the promise of a good thing, or terrified by the apprehension of danger, without thinking of any particular good or evil that is likely to befal us. What this idea of good or evil, which is not particular, can be, other than abstract, I cannot conceive; and to say that it is not an idea, but a mere feeling excited by custom, is an answer very little to the purpose. For this feeling, this custom, is itself a general impression, and could not, without a power of abstraction in the mind, think, without a power of being acted upon by a number of different impulses of pleasure and pain, concurring
