 Your lordship’s proof here brought out of my Essay, concerning the sun, I humbly conceive will not reach it; because what is said there, does not at all concern the real, but nominal essence; as is evident from hence, that the idea I speak of there, is a complex idea; but we have no complex idea of the internal constitution, or real essence of the sun. Besides, I say expressly, that our distinguishing substances into species by names, is not at all founded on their real essences. So that the sun being one of these substances, I cannot, in the place quoted by your lordship, be supposed to mean by essence of the sun, the real essence of the sun, unless I had so expressed it. But all this argument will be at an end, when your lordship shall have explained what you mean by these words, “true sun.” In my sense of them, any thing will be a true sun, to which the name sun may be truly and properly applied; and to that substance or thing, the name sun may be truly and properly applied, which has united in it that combination of sensible qualities, by which any thing else that is called sun is distinguished from other substances, i.e. by the nominal essence…. (Locke, Works, vol. IV, pp. 83–4)