Synopsis.

1. Retrospect.
2. Prospect.

THE last proposition has brought us to a point whence a look backwards, and another forwards, become necessary in order to clear away natural misgivings that we may be wandering about aimlessly. We have travelled together through regions of our own experience as knowledge-gathering creatures; we have noted down the general characteristics of certitude and of its allied or opposed states, but have avoided details. The consequence may be that some of the company have felt uneasy, and would over and over again have liked to pause on some such questions as, how the reports of the senses are to be credited, or how abstract and general ideas are valid, which confessedly have corresponding to them no abstract and general objects. But steadily and inexorably the surveying party has been led on, with the promise that another survey shall be made to fill in details, and with the declaration that, meanwhile, human certitude, before our philosophizing about it, sufficiently attests its own validity.

1. We have mapped out some of the general features of human knowledge, and spreading out the unfinished sketch, we observe what we have done. Beginning with logical truth, that is, with the knowing of truth, we decided, that apart from any theory as to how the mind can produce a resemblance of the several objects which it knows, yet we cannot intelligibly admit that it really knows anything while we deny that the knowledge bears any likeness to the thing known. Some sort of likeness there must be, though after a peculiar mode which our imitative arts cannot copy. Mere concomitant variation in mind and object will not suffice, if it is declared to carry no resemblance.

Inquiring next what is the special act of mind in which logical truth is to be found in its fulness, we settled that it must be the judgement, the act by which we affirm or deny, by which we are conscious that something is, or is not. Unless we go as far as this point, we are not yet in possession of a truth at best we are on the way to possession.

The conscious, full, and firm possession of the truth, to the exclusion of doubt, is certitude, a state of mind which we contrasted with ignorance, and with mere tendencies to assent, or assents given as to probabilities only. To distinguish these states belongs to the logician, though it is not his province to determine, in all fields of knowledge, what is the measure of assent or dissent due to any given statement. As a matter of self-analysis, a man maybe ought to sometimes be puzzled whether or not put aside suggested reasons for doubt, as being quite neutralised by contrary reasons; and in cases of such perplexity he will often have to appeal to considerations more concrete than logic supplies.

Returning to certitude we gave its broad distinction into natural and artificial, non-scientific and scientific, philosophic and common-sense; and we showed the interdependence between the two. Either branch -- but we have regard especially to the second -- is divisible according to its specific motive, into three kinds, metaphysical, physical, and moral. We likewise saw in what sense a proposition, which is certain, may be regarded as having its certitude greater or less.

In absolute opposition to certitude came scepticism under its most uncompromising form, or total negation of the power of mind to acquire real knowledge of things. Such scepticism was shown to be quite indefensible as a position taken up and defended by argument; its very possibility was denied in view of the irresistible self-assertion of a reasonable nature. However, there was a scepticism calling itself methodic, and professing to lead to the most legitimate dogmatism; but its professions proved hollow, and its failure served only to confirm our own previous proposition, that philosophy must build on natural certitude. In the words of Mr. Spencer, the philosophy of certitude "can be nothing but the analysis of our knowledge by means of our knowledge, an inquiry by our intelligence into the decisions of our intelligence." We cannot carry on such an inquiry without taking for granted the trustworthiness of our intelligence. But against any one supposing that this assumption itself is a blind, instinctive process, we entered our "caveat" not without call.

Having rejected the Cartesian primary facts and principles, as explained by their author, we felt bound to agree upon some of our own; and as primary truths we assigned what were called the First Fact,the First Condition, the First Principle; to which trio the Principle of Sufficient Reason was added. Out of these elements we cannot hope to buildup a system as Euclid built up his geometry; but so far as the logic of certitude is reducible to a few elements, these are they. We need hardly try to make all that Hamilton has made out of the Principle of Identity; because so far as what he says has truth in it, the truth seems scarce worth such explicit proclamation; or at any rate, it is very calculated to vex the souls of some readers. In behalf of our own primaries, the defence is available, that they are evident without demonstration, and that no one can argue against them without implicitly affirming them.

2. Thus far we have gone; but what is to be the next step? Many schoolmen follow the plan of entering here upon the consideration of what they call the means or the sources of knowledge. Their work comes pretty much to a division and a defence of faculties which successively take up the elements of knowledge, and bring them out in the shape of formed propositions. A justification is attempted of sensations, ideas, memory, judgment, and reasoning. But without a word of condemnation for the method of others, we may relegate these matters to the Second Part; the reason being that they may fairly be regarded as belonging to the details of the Subject, not to that most general description of Certitude which forms the First Part. As belonging to the latter, however, we will at once grapple with a question often delayed till the very end of the treatise, namely, with Evidence, considered as the objective criterion of truth. Since this is the perfectly general criterion of all certitude, we are justified in putting it along with the other matters which we have called "Generalities." There will thus be a book on Generalities and a book on Particularities; after which the reader will not be asked to extend his patient efforts to yet another book.