NECESSITY. 297 on that date have, when they fall, a peculiar quality the feeling of presence. But if. on the other hand, by ' eternal ' truths be meant truths which are true at no moment of time, then it would seem that in the same sense all truths are true at no moment of time. This is, indeed, only a more accurate way of expressing that same property of truths, which is popularly expressed by saying that they are always true. For a truth is not to be regarded in the same way either as a particular configuration of matter which may exist at one moment and cease to exist at the next, nor yet as matter itself, when it is conceived to exist at every moment. The truth that some- thing exists, it would seem, never does exist itself, and hence cannot be accurately said to occupy any moment of time. Accurately we should express that eternity, which is the property of all truths, by the negative statement that they are incapable of change, without thereby implying that they are capable of duration. Eternity, then, will not distinguish the Law of Contra- diction from any other truth ; and yet we should be un- willing to say that it was not necessary in a sense in which some other truths may be distinguished from it. Perhaps, absolute certainty will furnish this distinguishing mark. Now if absolute certainty be understood in a psychological sense, it will not furnish a universal mark. That we are more certain of the Law of Contradiction than of any other truth, I will admit, though it would be difficult to prove it. But then it must be admitted, on the other side, that there was a time in the history of the race when men were very certain of many, particularly the most contingent, truths, before they had even thought of the Law of Contradiction ; when, therefore, they could not be certain of it at all. It is, indeed, remarkable that all the truths, which we now con- sider particularly necessary, are so abstract that we cannot suppose them to have been thought of or believed in till after many other truths had enjoyed a long lease of certainty. That necessary truths are, then, universally more certain than others, cannot be maintained ; and if it be said that nevertheless, as soon as both are thought of, the necessary ones become at once more certain, or that they are capable of .greater certainty, it is fair to suspect that this is said on the a priori ground that, since they are more necessary, they must be more certain. Empirical evidence of it is certainly not forthcoming. Yet no one would hesitate to say, for the lack of this, that necessary truths do differ from others. It would seem, then, that certainty, in any psychological sense,