and can never feel what is past. The very fact of feeling anything shows, with absolute certainty, that the thing felt is present. But a very little thought about our faculty of memory shows that by its aid our intellect can perceive with certainty that which is not present-such as some past event of our lives-and that which is not, and never could be felt-namely, our own continuous being. But some one may say that our continuous being can be felt because our own body can be felt, and continuously felt for a considerable time, so that we are under no obligations to memory in recognizing our continuous existence. Our own body can, of course, be felt in different ways at once, and our experiences in feeling it can be indefinitely repeated or prolonged. But each time we feel it, we can but have the present feeling, and, apart from memory and reflex acts of the mind, we cannot know its existence as continuous and enduring. Our persistent body, once more, can easily be felt, but it can never be "felt" as enduring, although it can be "recognized" as enduring by the help of repeated sensations, when these are accompanied by acts of memory and of mental reflection. This power which memory possesses of lifting us, as it were, out of our present selves, and showing us a wide field of things external to our own minds, which things, but for memory, we could never recognize, is a very wonderful power. It is so wonderful that some persons feel tempted by its inexplicable character to doubt the veracity of their faculty of memory, or even to verbally deny it. But, as we have seen, they cannot do so without contradicting themselves, and committing intellectual suicide by falling into the fatuous system of general scepticism. The self-evident truth that our memory is trustworthy is a fact involved in, and absolutely necessary to, the full recognition of the first and most certain of all facts for us the fact of our own existence.

The certainty of these two preliminary facts being clearly seen, we may next proceed, in our quest for truth, to inquire about those supremely certain general truths or principles which were declared, towards the end of the first chapter, to be so fundamental that, without them, all advance in knowledge is absolutely impossible.

CHAPTER IV.

HOME TRUTHS.

The primary abstract general principle is the law of contradiction, which is self-evident and cannot be denied without involving absolute scepticism. Other self-evident abstract general principles are the axiom about the equality of things equal to a third thing, and the law of causation.

First general principle, the law of contradiction-Difficulties in its acceptation-A mistaken principle proposed in place of it-Denial of the law involves absolute scepticism-An objection-What produces a feeling of uncertainty about the law-Knowledge of universal truths not exceptionally wonderful-Second general principle, an axiom about equality-A fallacious objection-Third general principle, the law of causation-The idea of "power" or "force"-An objection and its answer.

WE have now advanced two distinct preliminary steps in our pursuit of truth; for we have recognized the certainty of two fundamental, self-evident facts, namely, the facts of our own existence, and of memory's trustworthiness. But in our first chapter it was pointed out* that, besides self-evident facts, a perception of two other orders of self-evident truths must lie at the root of all certainty. One of these two orders of truths concerned the force and validity of certain arguments. We shall consider those arguments in the next chapter. The other order of self-evident truths consisted of general, abstract principles or laws, and it is to the consideration of two or three of such laws that we must now address ourselves. It is plain, indeed, that we cannot build up a temple of truth with See above, p. 12.

general

the law of

tion.

nothing but "facts," however numerous and solid they may be. To do that we also need the aid of luminous general principles to guide us in the arrangement of our facts, and valid reasoning to connect them firmly together. In our endeavour to show clearly that there is such a thing as certainty, some very plain truths were cited,* as examples of matters about which no sane person can doubt; and in explaining the nature of "abstract truths," or "general laws," or "general principles," or "necessary truths," two truths were selected, which it will suit our purpose to here somewhat dilate upon. The first of these two thus First selected abstract truths is called "the law of contradiction," principle, and may be thus expressed: "A thing cannot, at one and contradic the same time, both be and not be." If we reflect upon this truth we shall see that it is an absolute and necessary one-that it must be true even to the remotest regions of space, and that it must be true both for all the ages that have past and for all the ages that are yet to come. But some readers may here once more be tempted to impatience at being asked to reflect about anything, the truth of which is so manifestly undeniable. In deprecation of such impatience, we would again urge the same considerations as we before urged ‡ in deprecation of impatience respecting our inquiry as to the possibility of self-knowledge. Other readers may feel discouraged because they do not at once see the universal necessity of the law of contradiction. possible that some persons may doubt as to how things in this respect now are in the Dog Star, or how they have been in this part of space during some unimaginable abyss of past time, ages before the beginning of our world's separate existence. It does, indeed, at first seem not a little difficult to believe that a creature of the very limited powers which man possesses can know such a thing as absolute, necessary, and universal truth. How, it may be asked, pifficulties can a being who, for a few fleeting moments, dwells in an acceptation. inconspicuous atom of a boundless universe, know that anything whatever is and must be true for all ages, and for every possible region of that universe, however eternally

in its

seems here to characterize the sceptic, and rash presumption the dogmatist. Nevertheless, if instead of considering this truth in its abstract form, we examine it in one of its concrete instances, its certainty will become clearly manifest. For example, let any one who doubts if something somewhere may not both "be" and "not be," consider whether it is possible for him (according to the illustration before given) both to possess his two eyes here and now, and at the same time to have only one of them; let him also think whether he could do so any better in any other place than the place where he is, or whether it could have been possible for him at any other time which he can conceive of. Again, let him ask himself whether he could both have lived in the reign of Edward III., and yet have never lived at all till the reign of Queen Victoria. He will, surely, then see clearly that this is impossible to him, as also that what is thus impossible for him, is impossible for other men also. But that abstract truth, the law of contradiction just quoted, is but the summing-up in one general expression of all concrete, separate cases of this kind.

Here, however, another objection may occur to the reader. He may say, "It is very true that I cannot imagine having two eyes and only one eye at the same time, and so I must practically acquiesce in the statement that we cannot simultaneously have both eyes and only one, simply because I am compelled thereto by my inability to imagine otherwise." But so to represent the matter, is to represent it not only inadequately but in a mistaken way, the error of which requires to be pointed A mistaken out, and ought to be clearly seen. It needs to be so seen principle proposed in because this mistaken representation is by some persons place of it. considered to be a supreme and ultimate rule of truth, and, in place of the law of contradiction, it has been laid down that "we must accept as true, propositions we cannot help thinking, because we cannot imagine the contrary." But if the reader will reflect over what his mind tells him when it unmistakably pronounces that he cannot, at the same time, both have eyes in his head and not have them, he will see that this perception of his is a clear positive

perception of incompatibility and consequent positive impossibility. He will not find his mind become a blank, and declare nothing but its own inability to answer, as he will find it do if he asks himself, "What is the disposition of the surface of the invisible side of the moon?" or, "Is the number of the heavenly bodies odd or even?" His mind has indeed been active, and not impotent; it has not declared that it was unable to answer his question, but has declared very clearly that he positively cannot have two eyes and, at the same time, have none, or only one. In other words, it has in this concrete instance, as in every other such instance, implicitly affirmed the law of contradiction. There are many things which we cannot think, merely through an impotence-a negative, passive inability, -to think them; as when we cannot think of all the units one after another, which would make a million. But such an impotence is a very different thing from positively seeing that anything cannot be because it is positively impossible. This truth will be further illustrated when we come to speak of the distinction between our powers of imagination and of intellectual conception. To say merely, "We cannot conceive the contrary of such proposition," is to make a mere assertion of inability, and is therefore a quite inadequate description of that active power of positive perception which we all act upon when we have to choose between two alternatives. A mere mental impotence will not guide us in our actions, but our actions are constantly guided by our implicit conviction of the truth expressed in the law of contradiction, though we may never in our lives have explicitly recognized it, or ever heard a word about it. The simplest rustic knows that if his wages have been paid to him, they are no longer owing, and that if he has put his cart horse in the stable, it is no longer between the shafts. The most learned of mankind are, of course, likewise continually guided in like manner, and to such guidance we owe every scientific deduction. If, then, perceptions of the kind were due to a mere mental disability, we might well exclaim, not "Oh, holy simplicity!" but "Oh, most mighty impotence!"