The freshness of the heart can fall like dew,
Which out of all the lovely things we see
Extracts emotions beautiful and new,
Hived in our bosoms like the bag o' the bee:
Think'st thou the honey with those objects grew?
Alas! 'twas not in them, but in thy power
To double even the sweetness of a flower.”
Through all that I have said hitherto I hope I have placed in a clear light the important truth that since all abstract knowledge springs from knowledge of perception, it obtains its whole value from its relation to the latter, thus from the fact that its conceptions, or the abstractions which they denote, can be realised, i.e., proved, through perceptions; and, moreover, that most depends upon the quality of these perceptions. Conceptions and abstractions which do not ultimately refer to perceptions are like paths in the wood that end without leading out of it. The great value of conceptions lies in the fact that by means of them the original material of knowledge is more easily handled, surveyed, and arranged. But although many kinds of logical and dialectical operations are possible with them, yet no entirely original and new knowledge will result from these; that is to say, no knowledge whose material neither lay already in perception nor was drawn from self-consciousness. This is the true meaning of the doctrine attributed to Aristotle: Nihil est in intellectu, nisi quod antea fuerit in sensu. It is also the meaning of the Lockeian philosophy, which made for ever an epoch in philosophy, because it commenced at last the serious discussion of the question as to the origin of our knowledge. It is also principally what the “Critique of Pure Reason” teaches. It also desires that we should not [pg 259] remain at the conceptions, but go back to their source, thus to perception; only with the true and important addition that what holds good of the perception also extends to its subjective conditions, thus to the forms which lie predisposed in the perceiving and thinking brain as its natural functions; although these at least virtualiter precede the actual sense-perception, i.e., are a priori, and therefore do not depend upon sense-perception, but it upon them. For these forms themselves have indeed no other end, nor service, than to produce the empirical perception on the nerves of sense being excited, as other forms are determined afterwards to construct thoughts in the abstract from the material of perception. The “Critique of Pure Reason” is therefore related to the Lockeian philosophy as the analysis of the infinite to elementary geometry, but is yet throughout to be regarded as the continuation of the Lockeian philosophy. The given material of every philosophy is accordingly nothing else than the empirical consciousness, which divides itself into the consciousness of one's own self (self-consciousness) and the consciousness of other things (external perception). For this alone is what is immediately and actually given. Every philosophy which, instead of starting from this, takes for its starting-point arbitrarily chosen abstract conceptions, such as, for example, absolute, absolute substance, God, infinity, finitude, absolute identity, being, essence, &c., &c., moves in the air without support, and can therefore never lead to a real result. Yet in all ages philosophers have attempted it with such materials; and hence even Kant sometimes, according to the common usage, and more from custom than consistency, defines philosophy as a science of mere conceptions. But such a science would really undertake to extract from the partial ideas (for that is what the abstractions are) what is not to be found in the complete ideas (the perceptions), from which the former were drawn by abstraction. The possibility of the syllogism leads to this mistake, because [pg 260] here the combination of the judgments gives a new result, although more apparent than real, for the syllogism only brings out what already lay in the given judgments; for it is true the conclusion cannot contain more than the premisses. Conceptions are certainly the material of philosophy, but only as marble is the material of the sculptor. It is not to work out of them but in them; that is to say, it is to deposit its results in them, but not to start from them as what is given. Whoever wishes to see a glaring example of such a false procedure from mere conceptions may look at the “Institutio Theologica” of Proclus in order to convince himself of the vanity of that whole method. There abstractions such as “ἑν, πληθος, αγαθον, παραγον και παραγομενον, αυταρκες, αιτιον, κρειττον, κινητον, ακινητον, κινουμενον” (unum, multa, bonum, producens et productum, sibi sufficiens, causa, melius, mobile, immobile, motum), &c., are indiscriminately collected, but the perceptions to which alone they owe their origin and content ignored and contemptuously disregarded. A theology is then constructed from these conceptions, but its goal, the θεος, is kept concealed; thus the whole procedure is apparently unprejudiced, as if the reader did not know at the first page, just as well as the author, what it is all to end in. I have already quoted a fragment of this above. This production of Proclus is really quite peculiarly adapted to make clear how utterly useless and illusory such combinations of abstract conceptions are, for we can make of them whatever we will, especially if we further take advantage of the ambiguity of many words, such, for example, as κρειττον. If such an architect of conceptions were present in person we would only have to ask naively where all the things are of which he has so much to tell us, and whence he knows the laws from which he draws his conclusions concerning them. He would then soon be obliged to turn to empirical perception, in which alone the real world exhibits itself, from which those conceptions are drawn. Then we would only [pg 261] have to ask further why he did not honestly start from the given perception of such a world, so that at every step his assertions could be proved by it, instead of operating with conceptions, which are yet drawn from perception alone, and therefore can have no further validity than that which it imparts to them. But of course this is just his trick. Through such conceptions, in which, by virtue of abstraction, what is inseparable is thought as separate, and what cannot be united as united, he goes far beyond the perception which was their source, and thus beyond the limits of their applicability, to an entirely different world from that which supplied the material for building, but just on this account to a world of chimeras. I have here referred to Proclus because in him this procedure becomes specially clear through the frank audacity with which he carries it out. But in Plato also we find some examples of this kind, though not so glaring; and in general the philosophical literature of all ages affords a multitude of instances of the same thing. That of our own time is rich in them. Consider, for example, the writings of the school of Schelling, and observe the constructions that are built up out of abstractions like finite and infinite—being, non-being, other being—activity, hindrance, product—determining, being determined, determinateness—limit, limiting, being limited—unity, plurality, multiplicity—identity, diversity, indifference—thinking, being, essence, &c. Not only does all that has been said above hold good of constructions out of such materials, but because an infinite amount can be thought through such wide abstractions, only very little indeed can be thought in them; they are empty husks. But thus the matter of the whole philosophising becomes astonishingly trifling and paltry, and hence arises that unutterable and excruciating tediousness which is characteristic of all such writings. If indeed I now chose to call to mind the way in which Hegel and his companions have abused such wide and empty abstractions, I should have to fear that [pg 262] both the reader and I myself would be ill; for the most nauseous tediousness hangs over the empty word-juggling of this loathsome philophaster.
That in practical philosophy also no wisdom is brought to light from mere abstract conceptions is the one thing to be learnt from the ethical dissertations of the theologian Schleiermacher, with the delivery of which he has wearied the Berlin Academy for a number of years, and which are shortly to appear in a collected form. In them only abstract conceptions, such as duty, virtue, highest good, moral law, &c., are taken as the starting-point, without further introduction than that they commonly occur in ethical systems, and are now treated as given realities. He then discusses these from all sides with great subtilty, but, on the other hand, never makes for the source of these conceptions, for the thing itself, the actual human life, to which alone they are related, from which they ought to be drawn, and with which morality has, properly speaking, to do. On this account these diatribes are just as unfruitful and useless as they are tedious, which is saying a great deal. At all times we find persons, like this theologian, who is too fond of philosophising, famous while they are alive, afterwards soon forgotten. My advice is rather to read those whose fate has been the opposite of this, for time is short and valuable.
Now although, in accordance with all that has been said, wide, abstract conceptions, which can be realised in no perception, must never be the source of knowledge, the starting-point or the proper material of philosophy, yet sometimes particular results of philosophy are such as can only be thought in the abstract, and cannot be proved by any perception. Knowledge of this kind will certainly only be half knowledge; it will, as it were, only point out the place where what is to be known lies; but this remains concealed. Therefore we should only be satisfied with such conceptions in the most extreme case, and when we have reached the limit of the knowledge possible to [pg 263] our faculties. An example of this might perhaps be the conception of a being out of time; such as the proposition: the indestructibility of our true being by death is not a continued existence of it. With conceptions of this sort the firm ground which supports our whole knowledge, the perceptible, seems to waver. Therefore philosophy may certainly at times, and in case of necessity, extend to such knowledge, but it must never begin with it.