201. If Hume were consistent in allowing no other determination to the impression than that of its having the maximum of vivacity, or to other modes of consciousness than the several degrees of their removal from this maximum, he would certainly have avoided the difficulties which attend Locke’s use of the metaphor of impression, while at the same time he would have missed the convenience, involved in this use, of being able to represent the primitive consciousness as already a recognition of a thing impressing it, and thus an ‘idea of a quality of body.’ But at the outset he remarks that ‘the examination of our sensations’ (_i.e._ our impressions of sensation) ‘belongs more to anatomists and natural philosophers than to moral,’ and that for that reason he shall begin not with them but with ideas. [1] Now this virtually means that he will begin, indeed, with the feelings he finds in himself, but with these as determined by the notion that they are results of something else, of which the nature is not for the present explained. Thus, while he does not, like Locke, identify our earliest consciousness with a rough and ready physical theory of its cause, he gains the advantage of this identification in the mind of his reader, who from sensation, thus apparently defined, transfers a definiteness to the ideas and secondary impressions as derived from it, though in the sequel the theory turns out, if possible at all, to be at best a remote result of custom and association. We shall see this more clearly if we look back to the general account of impressions and ideas quoted above. ‘An impression first strikes upon the senses and makes us perceive pleasure or pain, of which a copy is taken by the mind,’ called an idea. Now if we set aside the notion of a body making impact upon a sensuous, and through it upon a mental, tablet, pleasure or pain _is_ the impression, which, again, is as much or as little in the mind as the idea. Thus the statement might be re-written as follows:--‘Pleasure or pain makes the mind perceive pleasure or pain, of which a copy is taken by the mind.’ This, of course, is nonsense; but between this nonsense and the plausibility of the statement as it stands, the difference depends on the double distinction understood in the latter--the distinction _(a)_ between the producing cause of the impression and the impression produced; and _(b)_ between the impression as produced on the senses, and the idea as preserved by the mind. This passage, as we shall see, is only a sample of many of the same sort. Throughout, however explicitly Hume may give warning that the difference between impression and idea is only one of liveliness, however little he may scruple in the sequel to reduce body and mind alike to the succession of feelings, his system gains the benefit of the contrary assumption which the uncritical reader is ready to make for him. As often as the question returns whether