"So that if any one will examine himself concerning his notion of pure Substance in general, he will find he has no other idea of it at all but only a supposition of he knows not what Support of such qualities which are capable of producing simple ideas in us; which qualities are commonly called Accidents. If any one should be asked what is the subject wherein Colour or Weight inheres, he would have nothing to say but the solid extended parts. And if he were demanded what is it that Solidity and Extension inhere in, he would not be in a much better case than the Indian who, saying that the world was supported by a great elephant, was asked what the elephant rested on? To which his answer was, a great tortoise. But, being again pressed to know what gave support to the broad-backed tortoise, replied, something, he knew not what. And thus here, as in all other cases, where we use words without having clear and distinct ideas, we talk like children; who, being questioned what such a thing is, which they know not, readily give this satisfactory answer, That it is something; which in truth signifies no more, when so used, either by children or men, but that they know not what, and that the thing they pretend to know and talk of is what they have no distinct idea of at all, and so are perfectly ignorant of it and in the dark." (Bk. II., ch. xxiii., § 2.) No wonder that the next step in philosophy was to get rid altogether of this "something, we know not what." For, if we know not what it is, how do we know that it exists, and is not a mere fiction of the Schools? This step was taken by Berkeley, as respects matter, and by Hume the same negative criticism which Berkeley confines to matter was boldly, and, as it seems to me, far less successfully and legitimately extended to mind. Indeed, were it not for his express assurance to the contrary, we should often be tempted to think that Locke himself regarded this distinction of Substance and Accident, so far, at least, as it affects Matter and its attributes, as untenable, and was anxious to insinuate a doubt as to the very existence of the "unknown somewhat."