achievements, – the united action of several individuals, the planned co-operation of many thousands, civilisation, the state; also science, the storing up of experience, the uniting of common properties in one concept, the communication of truth, the spread of error, thoughts and poems, dogmas and superstitions. The brute first knows death when it dies, but man draws consciously nearer to it every hour that he lives; and this makes life at times a questionable good even to him who has not recognised this character of constant annihilation in the whole of life. Principally on this account man has philosophies and religions, though it is uncertain whether the qualities we admire most in his conduct, voluntary rectitude and nobility of feeling, were ever the fruit of either of them. As results which certainly belong only to them, and as productions of reason in this sphere, we may refer to the marvellous and monstrous opinions of philosophers of various schools, and the extraordinary and sometimes cruel customs of the priests of different religions.
It is the universal opinion of all times and of all nations that these manifold and far-reaching achievements spring from a common principle, from that peculiar intellectual power which belongs distinctively to man and which has been called reason, ὁ λογος, το λογιστικον, το λογιμον, ratio. Besides this, no one finds any difficulty in recognising the manifestations of this faculty, and in saying what is rational and what is irrational, where reason appears as distinguished from the other faculties and qualities of man, or lastly, in pointing out what, on account of the want of reason, we must never expect even from the most sensible brute. The philosophers of all ages may be said to be on the whole at one about this general knowledge of reason, and they have also given prominence to several very important manifestations of it; such as, the control of the emotions and passions, the capacity for drawing conclusions and formulating general principles, even such as are true prior to all experience, and so forth. Still all their explanations of the peculiar nature of reason are wavering, not clearly defined, discursive, without unity and concentration; now laying stress on one manifestation, now on another, and therefore often at variance with each other. Besides this, many start from the opposition between reason and revelation, a distinction which is unknown to philosophy, and which only increases confusion. It is very remarkable that up till now no philosopher has referred these manifold expressions of reason to one simple function which would be recognised in them all, from which they would all be explained, and which would therefore constitute the real inner nature of reason. It is true that the excellent Locke in the “Essay on the Human Understanding” (Book II., ch. xi., §§ 10 and 11), very rightly refers to general concepts as the characteristic which distinguishes man from the brutes, and Leibnitz quotes this with full approval in the “Nouveaux Essais sur l'Entendement Humaine” (Book II., ch. xi., §§ 10 and 11.) But when Locke (in Book IV., ch. xvii., §§ 2 and 3) comes to the special explanation of reason he entirely loses sight of this simple, primary characteristic, and he also falls into a wavering, undetermined, incomplete account of mangled and derivative manifestations of it. Leibnitz also, in the corresponding part of his work, behaves in a similar manner, only with more confusion and indistinctness. In the Appendix, I have fully considered how Kant confused and falsified the conception of the nature of reason. But whoever will take the trouble to go through in this reference the mass of philosophical writing which has appeared since Kant, will find out, that just as the faults of princes must be expiated by whole nations, the errors of great minds extend their influence over whole generations, and even over centuries; they grow and propagate themselves, and finally degenerate into monstrosities. All this arises from the fact that, as Berkeley says, “Few men think; yet all will have opinions.”
The understanding has only one function – immediate knowledge of the relation of cause and effect. Yet the perception of the real world, and all common sense, sagacity, and inventiveness, however multifarious their applications may be, are quite clearly seen to be nothing more than manifestations of that one function. So also the reason has one function; and from it all the manifestations of reason we have mentioned, which distinguish the life of man from that of the brutes, may easily be explained. The application or the non-application of this function is all that is meant by what men have everywhere and always called rational and irrational.12
§ 9. Concepts form a distinct class of ideas, existing only in the mind of man, and entirely different from the ideas of perception which we have considered up till now. We can therefore never attain to a sensuous and, properly speaking, evident knowledge of their nature, but only to a knowledge which is abstract and discursive. It would, therefore, be absurd to demand that they should be verified in experience, if by experience is meant the real external world, which consists of ideas of perception, or that they should be brought before the eyes or the imagination like objects of perception. They can only be thought, not perceived, and only the effects which men accomplish through them are properly objects of experience. Such effects are language, preconceived and planned action and science, and all that results from these. Speech, as an object of outer experience, is obviously nothing more than a very complete telegraph, which communicates arbitrary signs with the greatest rapidity and the finest distinctions of difference. But what do these signs mean? How are they interpreted? When some one speaks, do we at once translate his words into pictures of the fancy, which instantaneously flash upon us, arrange and link themselves together, and assume form and colour according to the words that are poured forth, and their grammatical inflections? What a tumult there would be in our brains while we listened to a speech, or to the reading of a book? But what actually happens is not this at all. The meaning of a speech is, as a rule, immediately grasped, accurately and distinctly taken in, without the imagination being brought into play. It is reason which speaks to reason, keeping within its own province. It communicates and receives abstract conceptions, ideas that cannot be presented in perceptions, which are framed once for all, and are relatively few in number, but which yet encompass, contain, and represent all the innumerable objects of the actual world. This itself is sufficient to prove that the lower animals can never learn to speak or comprehend, although they have the organs of speech and ideas of perception in common with us. But because words represent this perfectly distinct class of ideas, whose subjective correlative is reason, they are without sense and meaning for the brutes. Thus language, like every other manifestation which we ascribe to reason, and like everything which distinguishes man from the brutes, is to be explained from this as its one simple source – conceptions, abstract ideas which cannot be presented in perception, but are general, and have no individual existence in space and time. Only in single cases do we pass from the conception to the perception, do we construct images as representatives of concepts in perception, to which, however, they are never adequate. These cases are fully discussed in the essay on the principle of sufficient reason, § 28, and therefore I shall not repeat my explanation here. It may be compared, however, with what is said by Hume in the twelfth of his “Philosophical Essays,” p. 244, and by Herder in the “Metacritik,” pt. i. p. 274 (an otherwise worthless book). The Platonic idea, the possibility of which depends upon the union of imagination and reason, is the principal subject of the third book of this work.
Although concepts are fundamentally different from ideas of perception, they stand in a necessary relation to them, without which they would be nothing. This relation therefore constitutes the whole nature and existence of concepts. Reflection is the necessary copy or repetition of the originally presented world of perception, but it is a special kind of copy in an entirely different material. Thus concepts may quite properly be called ideas of ideas. The principle of sufficient reason has here also a special form. Now we have seen that the form under which the principle of sufficient reason appears in a class of ideas always constitutes and exhausts the whole nature of the class, so far as it consists of ideas, so that time is throughout succession, and nothing more; space is throughout position, and nothing more; matter is throughout causation, and nothing more. In the same way the whole nature of concepts, or the class of abstract ideas, consists simply in the relation which the principle of sufficient reason expresses in them; and as this is the relation to the ground of knowledge, the whole nature of the abstract idea is simply and solely its relation to another idea, which is its ground of knowledge. This, indeed, may, in the first instance, be a concept, an abstract idea, and this again may have only a similar abstract ground of knowledge; but the chain of grounds of knowledge does not extend ad infinitum; it must end at last in a concept which has its ground in knowledge