When I say, with regard to any particular kind of value, that the question whether and in what degree anything possesses it _depends solely on the intrinsic nature of the thing in question_, I mean to say two different things at the same time. I mean to say (1) that it is _impossible_ for what is strictly _one and the same_ thing to possess that kind of value at one time, or in one set of circumstances, and _not_ to possess it at another; and equally _impossible_ for it to possess it in one degree at one time, or in one set of circumstances, and to possess it in a different degree at another, or in a different set. This, I think, is obviously part of what is naturally conveyed by saying that the question whether and in what degree a thing possesses the kind of value in question always depends _solely_ on the intrinsic nature of the thing. For if _x_ and _y_ have different intrinsic natures, it follows that _x_ cannot be quite strictly one and the same thing as _y_; and hence if _x_ and _y_ can have a different intrinsic value, only where their intrinsic natures are different, it follows that one and the same thing must always have the same intrinsic value. This, then, is part of what is meant; and about this part I think I need say no more, except to call attention to the fact that it involves a conception, which as we shall see is also involved in the other part, and which involves the same difficulty in both cases--I mean, the conception which is expressed by the word 'impossible.' (2) The second part of what is meant is that if a given thing possesses any kind of intrinsic value in a certain degree, then not only must that same thing possess it, under all circumstances, in the same degree, but also anything _exactly like_ it, must, under all circumstances, possess it in exactly the same degree. Or to put it in the corresponding negative form: It is _impossible_ that of two exactly similar things one should possess it and the other not, or that one should possess it in one degree, and the other in a different one.