We are thus led to recognise that cognition is, in all its various forms, essentially of one character. From the very first it is a process of discriminating, of distinguishing, of comparing; and, although in its earlier stages differing enormously in degree of completeness from those acts which we are in the habit of de scribing specifically as acts of comparing and relating, is yet similar to them. We are led, in short, to recognise that as we trace back the stages of mental development, we come upon a discriminative activity that evinces itself in ever simpler and more rudimentary forms,—k discriminative activity which is prior to that in which so-called "ideas of relation" are con sciously used, and on the basis of which these are subsequently formed and applied. We are returning, in fact, to the Aristo telian conception of cognitive activity as exhibiting ascending grades of scope and completeness, with, however, the important difference that we are not admitting, either at one end of the scale or at the other, a mode of apprehension that is intuitive in character as distinguished from what he too described as discriminative. The old Aristotelian difficulty recurs when it is claimed that there is a fundamental distinction to be drawn be tween "knowledge by acquaintance" and "knowledge by descrip tion," and that by the first we have immediate awareness of sense data and of, at least, certain universals, as contrasted with the mediate awareness of things and of truths which is obtained by the other.
There are specific reasons for doubting the tenability of this view. It is hard to realise what a cognitive act can be which does not involve those simple functions of discriminating which afterwards evince themselves in the highly developed forms of mental activity for which the name "thinking" or "judging" is usually reserved. There would seem, then, to be a continuous advance from the simplest forms of cognition to the higher forms, and the generalising work of thought does not leave perception itself unaffected; perception is no longer what it was in its cruder stages, it too comes to involve generalisation.
From the point of view here taken, the question as to the rela tion between thought and reality assumes an aspect altogether different from that which it assumed in any of the historic theories dealt with above. Thought cannot be regarded as constructive of the world of concrete fact in the way in which either Kant or Hegel conceived it to be, nor on the other hand, can there be that opposition between thought and concrete fact, which the empirical writers would constitute. Cognitive activity is one ingredient in the whole of existent reality, and as such can neither be identified with the whole nor divorced from it. It presupposes as conditions of its possibility existent entities other than itself, and there is something incongruous in the notion that thinking which is throughout determined by the concrete material of the world within which it makes its appearance should in its procedure thoroughly distort that material.
Here, once more, the problem of error rather than that of truth would appear to be the crucial problem. The errors to which perception, for example, is liable cannot be accounted for by any one mode of explanation ; there are numerous circumstances which, in each specific case, require to be considered. But if perception be of the nature indicated, if the characteristics are discriminated always in a more or less fragmentary fashion, and under some conditions much more imperfectly than under others, one general principle of explanation is at once provided. It is, indeed, precisely in the contrast between the fragmentary and the complete that the significance of what is denoted by the term "appearance" is to be discerned. In contradistinction to the fulness of content possessed by the existent object, the "appear ance" carries with it marks of poverty, of mutilation, and these may result in leading to positive error. Always in sense-perception there must, arise this contrast, but it does not imply that a new object, the "appearance," has come into existence, and is thence forward there ready to be apprehended whenever the opportu nity occurs. The "appearance" is no more than a way in which the existent object is known. And, mutatis mutandis, similar considerations hold with reference to the more developed pro cess of thinking.
In the long run, the limitation of our thought is a result of the position of the finite mind as part of the totality to which we give the name reality; the finite mind stands, as Lotze put it, not at the centre of things, but has a modest position somewhere in the extreme ramifications of reality. All the same, the cate gories of thought are not mere forms capriciously invented by finite minds. It is true that the relations of logical dependence which we represent by means of judgments and syllogisms are not to be regarded as precise copies of relations that subsist in the realm of concrete fact. But in the first place, we never in our thinking assume any such literal correspondence ; and, in the second place, the forms of thought are ways in which the modes of connectedness of concrete fact become intelligible to thinking minds and without which they would not become intelligible at all.
The distinction between truth and concrete fact comes most clearly to the front in what we call thinking ; but it is involved in the simplest processes of apprehension. And in this connection it seems advisable to add a word respecting one aspect of the opposition between perceiving and thinking which is frequently emphasised and to which reference has already been made. The contents of thought are representative of an order that is indepen dent of time. Temporal succession may be represented in and through the contents of thought, but taken in themselves, as concepts of universals, these contents are timeless. On the other hand, it is urged, perception is always apprehensive of chang ing fact, and is essentially concerned with temporal events.