will not believe that there can be limits to his outlook into her wide domains, nor pass from the objects of nature, which he can satisfactorily explain by means of observation and mathematical thought — which he can determine synthetically in intuition, to those which neither sense nor imagination can ever present in concreto; he will not concede the existence of a faculty in nature, operating independently of the laws of nature — a concession which would introduce uncertainty into the procedure of the understanding, which is guided by necessary laws to the observation of phenomena; nor, finally, will he permit himself to seek a cause beyond nature, inasmuch as we know nothing but it, and from it alone receive an objective basis for all our conceptions and instruction in the unvarying laws of things.
In truth, if the empirical philosopher had no other purpose in the establishment of his antithesis than to check the presumption of a reason which mistakes its true destination, which boasts of its insight and its knowledge, just where all insight and knowledge cease to exist, and regards that which is valid only in relation to a practical interest, as an advancement of the speculative interests of the mind (in order, when it is convenient for itself, to break the thread of our physical investigations, and, under pretence of extending our cognition, connect them with transcendental ideas, by means of which we really know only that we know nothing)— if, I say, the empiricist rested satisfied with this benefit, the principle advanced by him would be a maxim recommending moderation in the pretensions of reason and modesty in its affirmations, and at the same time would direct us to the right mode of extending the province of the understanding, by the help of the only true teacher, experience. In obedience to this advice, intellectual hypotheses and faith would not be called in aid of our practical interests; nor should we introduce them under the pompous titles of science and insight. For speculative cognition cannot find an objective basis any other where than in experience; and, when we overstep its limits our synthesis, which requires ever new cognitions independent of experience, has no substratum of intuition upon which to build.
But if — as often happens — empiricism, in relation to ideas, becomes itself dogmatic and boldly denies that which is above the sphere of its phenomenal cognition, it falls itself into the error of intemperance — an error which is here all the more reprehensible, as thereby the practical interest of reason receives an irreparable injury.
And this constitutes the opposition between Epicureanism57 and Platonism.
Both Epicurus and Plato assert more in their systems than they know. The former encourages and advances science — although to the prejudice of the practical; the latter presents us with excellent principles for the investigation of the practical, but, in relation to everything regarding which we can attain to speculative cognition, permits reason to append idealistic explanations of natural phenomena, to the great injury of physical investigation.
3. In regard to the third motive for the preliminary choice of a party in this war of assertions, it seems very extraordinary that empiricism should be utterly unpopular. We should be inclined to believe that the common understanding would receive it with pleasure — promising as it does to satisfy it without passing the bounds of experience and its connected order; while transcendental dogmatism obliges it to rise to conceptions which far surpass the intelligence and ability of the most practised thinkers. But in this, in truth, is to be found its real motive. For the common understanding thus finds itself in a situation where not even the most learned can have the advantage of it. If it understands little or nothing about these transcendental conceptions, no one can boast of understanding any more; and although it may not express itself in so scholastically correct a manner as others, it can busy itself with reasoning and arguments without end, wandering among mere ideas, about which one can always be very eloquent, because we know nothing about them; while, in the observation and investigation of nature, it would be forced to remain dumb and to confess its utter ignorance. Thus indolence and vanity form of themselves strong recommendations of these principles. Besides, although it is a hard thing for a philosopher to assume a principle, of which he can give to himself no reasonable account, and still more to employ conceptions, the objective reality of which cannot be established, nothing is more usual with the common understanding. It wants something which will allow it to go to work with confidence. The difficulty of even comprehending a supposition does not disquiet it, because — not knowing what comprehending means — it never even thinks of the supposition it may be adopting as a principle; and regards as known that with which it has become familiar from constant use. And, at last, all speculative interests disappear before the practical interests which it holds dear; and it fancies that it understands and knows what its necessities and hopes incite it to assume or to believe. Thus the empiricism of transcendentally idealizing reason is robbed of all popularity; and, however prejudicial it may be to the highest practical principles, there is no fear that it will ever pass the limits of the schools, or acquire any favour or influence in society or with the multitude.
Human reason is by nature architectonic. That is to say, it regards all cognitions as parts of a possible system, and hence accepts only such principles as at least do not incapacitate a cognition to which we may have attained from being placed along with others in a general system. But the propositions of the antithesis are of a character which renders the completion of an edifice of cognitions impossible. According to these, beyond one state or epoch of the world there is always to be found one more ancient; in every part always other parts themselves divisible; preceding every event another, the origin of which must itself be sought still higher; and everything in existence is conditioned, and still not dependent on an unconditioned and primal existence. As, therefore, the antithesis will not concede the existence of a first beginning which might be available as a foundation, a complete edifice of cognition, in the presence of such hypothesis, is utterly impossible. Thus the architectonic interest of reason, which requires a unity — not empirical, but a priori and rational — forms a natural recommendation for the assertions of the thesis in our antinomy.
But if any one could free himself entirely from all considerations of interest, and weigh without partiality the assertions of reason, attending only to their content, irrespective of the consequences which follow from them; such a person, on the supposition that he knew no other way out of the confusion than to settle the truth of one or other of the conflicting doctrines, would live in a state of continual hesitation. Today, he would feel convinced that the human will is free; tomorrow, considering the indissoluble chain of nature, he would look on freedom as a mere illusion and declare nature to be all-in-all. But, if he were called to action, the play of the merely speculative reason would disappear like the shapes of a dream, and practical interest would dictate his choice of principles. But, as it well befits a reflective and inquiring being to devote certain periods of time to the examination of its own reason — to divest itself of all partiality, and frankly to communicate its observations for the judgement and opinion of others; so no one can be blamed for, much less prevented from, placing both parties on their trial, with permission to end themselves, free from intimidation, before intimidation, before a sworn jury of equal condition with themselves — the condition of weak and fallible men.
57 It is, however, still a matter of doubt whether Epicurus ever propounded these principles as directions for the objective employment of the understanding. If, indeed, they were nothing more than maxims for the speculative exercise of reason, he gives evidence therein a more genuine philosophic spirit than any of the philosophers of antiquity. That, in the explanation of phenomena, we must proceed as if the field of inquiry had neither limits in space nor commencement in time; that we must be satisfied with the teaching of experience in reference to the material of which the world is posed; that we must not look for any other mode of the origination of events than that which is determined by the unalterable laws of nature; and finally, that we not employ the hypothesis of a cause distinct from the world to account for a phenomenon or for the world itself — are principles for the extension of speculative philosophy, and the discovery of the true sources of the principles of morals, which, however little conformed to in the present day, are undoubtedly correct. At the same time, any one desirous of ignoring, in mere speculation, these dogmatical propositions, need not for that reason be accused of denying them.