ters of fact, and relations of ideas. The former are, one and all of them, whatever we have experienced— whatever we know by experience: and experience, as medium of knowledge, is sense, principally external, but also, as understood by Locke and Kant, internal. The sun shines, stones fall, fire burns, wood floats, &c. &c. &c.; and the truth of all such propositions, or the fact they name, is only known by trial, and trial is but another word for experience. We have actually experienced the event, and-to signalise the shade between the two words-we can, at any time, try it. Of all such propositions, it is seen that they are true; but it is not seen that they are necessarily, or must be, true. That is, no reason is seen why they are true; and, consequently, what is the same thing, their contrary implies no contradiction, and is equally possible. The contraries, for example, the sun does not shine, stones do not fall, fire does not burn, wood does not float, &c. &c. &c., we know by experience, by trial, to be untrue; but they are not contradictions to thought, they are not impossible, they are still conceivable (as really, perhaps, some woods do not burn); and they depend wholly and solely on the state of the case, which is, once for all, found to be so and so and not otherwise. Now truths of this nature the former class, the matters of fact-are named by Hume (with reference to their validity, or peculiar evidence) contingent, and by Kant (with reference to their source experience, to the after the fact that is in them) à posteriori.

The latter class, again, the relations of ideas, are

widely different; and, in the words of Hume, consist of 'every affirmation which is either intuitively or demonstratively certain.' Indeed, seeing that whatever is demonstratively certain rests at last on what is intuitively certain, we may withdraw the former as superfluous, and define relations of ideas to be, all affirmations that are intuitively certain. Of this class all the axioms and propositions of mathematics are examples. The whole is greater than its part, for instance: for the proof of this, we do not refer to experience, to trial; we do not say that it just is so, that this is just the fact; we know that it, not only is so, but necessarily is so; we know the reason why it is so; and we know that its contrary (the whole is not greater than its part) implies a contradiction, and is by necessity impossible. This class, then, with reference to their validity are named necessary and universal, or apodictic, truths, and (by Kant), with reference to their independence of sense-of any trial or experience of sense-as source (the before the fact, or the independence of the fact), à priori truths.

There is good reason for believing, we may remark, that Hume, in using the word intuitive, attached to it that evidence, vision, insight—that actual perception and looking-at-which Kant always had before him in the German word for intuition-Anschauung. Indeed, it is pretty certain that their common predecessor, Locke, entertained the same view. Many a one,' he says (Book iv. c. vii. s. 10), 'knows that one and two are equal to three, without having heard or thought on that or any other axiom by which it might be

proved; and knows it as certainly as any other man knows that the whole is equal to all its parts, or any other maxim, and all from the same principle of selfevidence; the equality of those ideas being as visible and certain to him, without that or any other axiom, as with it,-it needing no proof to make it perceived.' On the other hand, it seems to have been Reid who, through his definition of intuitive propositions as 'propositions which are no sooner understood than they are believed,' has made almost universally current since his time a somewhat different sense of the word— the 'no sooner,' that is, or the immediacy and instantaneousness, as it were the instinctivity, which it also implies.

Hume, then, had the actual perception that an intuition involves well before his mind, though it rose not up to him, perhaps, as that express inspection which Kant considered it. He had in mind, not the instantaneousness of the insight only, but this insight itself. Intuitive truths, then, are truths that are seen,-truths that are seeingly believed, not truths that, as incomprehensible, must be unseen, and, if believed, can only be unseeingly believed. That the straight line is the shortest, requires no proof; but, for all that, it wants not evidence; it is no incomprehensible truth that rests on a blind belief alone; it is not only believed to be true, but it is seen to be true.*

Hume further characterises these truths of the second class thus:- Propositions of this kind are

*See Note at end.

discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe: though there never were a true circle or triangle in nature, the truths demonstrated by Euclid would for ever retain their certainty and evidence.' Here Hume plainly intimates, not only that he knows such truths to bring evidence, but to be also à priori

'discoverable by thought,' that is, without any reference to, or direct trial of, anything actually in nature. We may regard, indeed, the à priori of Kant to have taken birth in this passage of Hume. Probably we know now, then, something of the true nature of those primary truths to which Hamilton's third characteristic sign applies, and will be able to judge of his relative utterances.

6

Now, we have to point out at once that these four characteristic signs of Hamilton are enumerated by him as referring to all primary truths indiscriminately alike. Of this we cannot doubt. He expressly (Reid's Works, p. 743, note) affirms of the primary truths of fact, and of the primary truths of intelligence (the contingent and necessary truths of Reid),' that, though 'two very distinct classes of the original beliefs or intuitions of consciousness,' 'there appears no sufficient ground to regard their sources as different. After this, it is not difficult for us to understand that Hamilton, in what seems to have been almost his one action on the platform of common sense, saw no contradiction in asserting the cognition of a material non-ego to be a universal and necessary first principle -an apodictic datum of consciousness. But, of this

one action, if the first half-the postulate of a stationary consciousness, namely-be absurd, no less absurd is the second, that would elevate into the universal, necessary, and à priori validity of a relation of ideas, the matter of fact which is contained in our contingent, sensuous, and à posteriori cognition of the material world.* Consider together the averments: -A straight line is the shortest, a straight line is not the shortest; and, There is a material non-ego, there is no material non-ego. The different validity is at once apparent. In truth, the two classes of evidence cannot be confounded; and Hamilton, whatever he may say about 'no sufficient grounds,' knows this well. In fact, there is hardly any distinction in Hamilton with which his reader is more familiar than that between necessity and contingency. He alludes to the successful application of it by Kant; in disparagement of Kant he points to it in Leibnitz; and he asserts for Reid in its regard-and again in disparagement of Kant, who in this shall have been 'indebted to Leibnitz'-'an original and independent discernment.' (It was plain for both Kant and Reid, in what was most familiar to both-Hume.)

But Hamilton is hardly more satisfactory in the remainder of his characteristic signs. Opposing the last to the first, for example, or even the second to

* That the cognition of a material non-ego is but empirical, requires no reference to authority; Reid, however, will be found to enumerate it among his contingent primary truths. (Reid's Works, p. 441.) Hamilton probably lays weight, as already said, on the complete generality of the non-ego; but there is no more reason for declaring consciousness inviolable as regards the general fact of a material non-ego, than as regards the movement of the sun, or the crookedness of an immersed stick.