other words, they do not make us know existing beings; but if they be joined to other particular ones, a reciprocal influence is established between them, from which cognition results. When we make the general affirmation: "Every contingent being requires a cause;" this proposition, although very true, means nothing in the order of facts, if we abstract the existence of contingent beings and causes of every kind. In such a case, the proposition will express a relation of ideas, not of facts: the cognition which results therefrom will be merely ideal, not positive.
91. This relation of ideas tacitly involves a condition, which gives them, so far as facts are concerned, a hypothetical value; for, when we affirm that every contingent being must have a cause, we are not to be understood to affirm a relation of ideas destitute of all possible application; but rather, on the contrary, to intend that if any contingent being exists, it must have a cause.
92. In order that this hypothetical value of ideas may be converted into a positive value, nothing is necessary but that the condition involved in the general proposition: "Every contingent being must have a cause," be verified. Of itself alone this teaches us nothing concerning the real world; but from the moment that experience shows us a single contingent being, the general proposition, before sterile, becomes exceedingly fruitful. So soon as experience shows us a contingent being, we know the necessity of its cause; we also infer the necessity of the proportions, which the activity producing must preserve with the thing produced; knowing the qualities of the latter, we infer those which ought to be found in the former. In this manner, resting upon two bases, one of which is ideal truth and the other real truth, or data supplied by experience, we construct a true positive science referred to determinate facts.
93. Since the being that thinks necessarily has consciousness of itself, no thinking being can be limited to the cognition of purely ideal truths. Even if we were to suppose it perfectly isolated from all other beings, in absolute non-communication with every thing not itself, so as neither to exert any influence upon them, nor to be influenced by them, it could not be reduced to the cognition of a purely ideal order; for, by the very fact that it is thinking, it is conscious of itself, and consciousness is essentially a particular fact, a cognition of a determinate being, since without it there could be no consciousness.
94. This observation overturns to its very foundation the system which pretends to bar all communication between the real and ideal orders. It shows also that experience is not only possible, but absolutely necessary to every thinking being, since consciousness is by its very nature an experience, and the clearest and surest experience. The truths of the ideal order are then necessarily interlinked with those of the real order: to suppose all intercommunication between them impossible, is to disown a fundamental fact of ideological and psychological science, consciousness.
95. To render the truth and exactness of the preceding doctrine more evident, let us suppose a man, or rather a human mind, absolutely ignorant of the existence of an external world, of every body, and even of every spirit; one that knows nothing concerning its own origin or destiny, but one that would nevertheless at the same time exercise its intellectual activity, without which it would be a lifeless thing, and could offer no field to observation. Let us suppose him to have general ideas, such as of being and of not-being, of substance and accidents, of the absolute and the conditioned, of the necessary and contingent. Manifestly he may combine them in various ways, and arrive at the same purely ideal results to which we ourselves arrive. There is no supposition more favorable to a series of abstract cognitions independent of experience, and yet not even in this case would the truths known be limited to the purely ideal order; it would even here be impossible for them not to descend to the real order, if the thinking being were not dispossessed of all consciousness of itself.
Indeed, by the very fact that a being is supposed capable of thinking, it is supposed able to say to itself, I think. This act is eminently experimental, and it needs only to be united with general truths in a common consciousness, to enable the isolated being to rise above itself, and create for itself a positive science, by which to pass from the world of ideas to that of facts. The instability of its thoughts, and the permanence of the being that experiences them, offer to it a practical case in which the general ideas of substance and accident are particularized. The successive appearance and disappearance of its own conceptions will show to it the ideas of being and of not-being realized; the recollection of the time when its own operations commenced, beyond which the memory of its existence does not extend, will enable it to know the contingency of his own being; and this fact, combined with the general principles which express the relations between contingent and necessary beings, will suggest to the thought that there must be another that communicated to it its existence.
CHAPTER XV.
ILLUSTRATIONS OF THE VALUE OF GENERAL CONCEPTIONS
96. However vague the ideas an isolated being would form of objects distinct from itself, they will never be so vague as not to refer to a real thing. The mind may not know the nature of this reality, but it knows for certain that it exists. A man blind from his birth can form no clear idea of colors, nor of the sensation of seeing; but is he therefore ignorant that sensation exists, and that the words, color, seeing, and others which refer to sight, have a positive and determinate object? Certainly not. The blind man does not know in what these things, of which he hears, consist, but he knows that they are something; those of his conceptions that refer to them may be called imperfect, but they are not vain; the words by which he expresses them, have for him a positive, although incomplete meaning.
97. There is a great difference between incomplete and indeterminate conceptions; the former may refer to a positive thing, although imperfectly known; the latter include nothing but a relation of ideas, meaning nothing in the order of facts. We will render this difference more apparent by explaining the example of the preceding paragraph.
A man blind from his birth has no intuition of colors, nor of any thing that refers to the sense of sight; but he is sure that there exist external facts which correspond to an internal affection called seeing. This idea is incomplete, but it has a determinate object. The words of those who possess the sense of sight reveal to him its existence; he knows not, what it is, but, that it is; in other words, he does not know its essence, but its existence. Let us now suppose the possibility of an order of sensations different from ours, and in nowise resembling those which we experience, to be called in question. The conception referred to the new sensations would not only be incomplete, but would have no relation to any real object. The general idea, then, of affection of a sensitive being, will be all that our mind will have; but it will know nothing of its existence, and can form only mere conjectures as to the conditions of its possibility. This example illustrates our idea. We find in the man blind from his birth, who hears of what pertains to the sense of sight, an incomplete conception, but one to which the existence of a series of facts, known to his mind, corresponds. But in ourselves, if we reflect upon a kind of sensations different from our own, we find conceptions, having, indeed, a general object, but of whose realization we know nothing.
98. Thus is it explained how our mind, without having intuition of a thing, can, nevertheless, know it, and be perfectly certain of its existence. We have here demonstrated that conceptions may, although they do not refer to a sensible intuition, have a value, not only in the order of ideas, but also in that of facts.
99. In order to prove the sterility of all conception beyond sensible intuition, Kant adduces one reason, which is, that we cannot define the categories and the principles which flow from them without referring to the objects of sensibility. This is no proof at all; for, in the first place, the impossibility of a definition does not always arise from the fact that the conception to be defined is empty; but it very frequently results from the conception being simple, and consequently not susceptible of a division into parts that may be expressed by words. How will he define the idea of being? No matter how he attempts to define it, the thing to be defined will enter into the definition: the words, thing, reality, existence, all signify being.
It is very natural, since
