proposition has no meaning, or rather its expression becomes impossible. The idea of subject involves the ideas of unity and substance, and that of thinking involves the idea of activity, or of passivity, so to speak, accompanied by consciousness.
183. To render the proposition possible, we must suppose the decomposition of the ideas to commence at some point, that is, either in the idea of the soul we find that of thinking, or in that of thinking we find that of the soul. Fixing ourselves in the soul, and abstracting thinking, we meet with the idea of subject, or of substance in general; and there, however much we cavil, we shall never find the idea of thinking. The soul in itself is not manifested to us; we know it by thought; in thought therefore we must fix the point of departure, not in the soul; wherefore in the above proposition, what is primitively known is rather the predicate than the subject; and of the two conceptions, that of subject has rather the character of a thing contained, than of a thing containing.
The soul by itself, so to speak, springs up with the presence of thought. If the intellectual activity is concentrated in search of its first basis, it finds it, not in the pure subject, but in its acts, that is, in its thoughts. These last are then the first object of reflective intellectual activity, its first element of combination, its first datum for the solution of the problem. Fixing its sight on this element, it discovers a unity in the midst of plurality, a being that remains the same through the ebb and flow of the phenomena of consciousness; and this identity is incontestably asserted by consciousness itself. The idea of the soul then is taken from that of thought, and consequently the subject springs from the predicate, rather than the predicate from the subject.
184. The thought from which we derive the idea of the soul is not thought in general, but thought realized, existing in ourselves. But this reality is sterile unless offered to the mind under a general idea; for it is evident that the soul does not come from one single act, since it is unity, the subject of plurality. To arrive at the idea of the soul we require unity of consciousness, and this we know only as we have experienced it, that is, so far as we perceive the relation of the one to the multiple, of a subject to its modifications.
Such elaboration is necessary to the production of so simple an expression as I think; and here we see how much reason there is to distinguish between the thing itself and the form, and how inconsiderately they act who confound things so different. Thus, from want of due analysis, they take in philosophy immense strides from one order to another, confound ideas and entangle matters.
185. To completely illustrate this matter, we will examine the relations of existence to thought; a very easy examination, if we bear in mind the observation just made.
It is certain that we conceive existence before thought: nothing can think without existing: existence is an indispensable condition to thought: to think and not to exist is a manifest contradiction. But what is first offered to our mind is not existence, but thought, and this not in the abstract, but determinate, experimental, or as the expression now is, empyrical. The idea of existence is general, includes all beings, and consciousness cannot commence with it. At one time we obtain this idea by abstraction; at another, it is a form pre-existing in our mind, not the first that occurs to us, or to speak more exactly, not the last point to be attained when we follow back the thread of our cognitions in order to discover their starting-point. This consciousness, when made objective, and when the conception which it offers is analyzed, presents to us the idea of existence as contained in itself.
Hence we infer that the therefore I exist is not, strictly speaking, a consequence of the I think, but the intuition of the idea of existence in that of thought. There are here two propositions per se notæ, as the scholastics say: the one general, the thinking is existing; the other particular, I thinking am existing. The first belongs to the purely ideal order, and is intrinsically evident, independently of all particular consciousness; the second participates of the two orders, the real and the ideal; the real, in so far as it includes the particular fact of consciousness; the ideal, in so far as it includes a combination of the general idea of existence with the particular fact; since thus only is the union of the predicate with the subject conceivable.
186. It will now be very easy to solve all the questions discussed in the schools.
First question. Does the principle I think depend on another? We answer with a distinction. If by this principle is meant the simple fact of consciousness, it evidently does not. For our understanding there is nothing prior to ourselves; whatever we know so far forth as known by us, supposes our consciousness; if we suppress it, we destroy every thing, and although we attempt to destroy every thing, it still remains indestructible, since it depends on nothing, presupposes nothing.
If by the principle I think is meant a proposition, it can only have proceeded from reasoning or analysis, and so cannot be the fundamental principle of our cognitions.
187. Second question. When the other principles are wanting, is this one also wanting? We must apply the same distinction here: as a simple fact? No! as a proposition? Yes! Deny every thing, even the principle of contradiction, and consciousness still subsists; but deny the principle of contradiction, and every proposition is destroyed, every combination becomes absurd: analysis, and the relation of the predicate with the subject, are unmeaning words.
188. Third question. Admitting the principle I think, can he who denies the others be reduced at least indirectly to truth? We again distinguish: you speak of reducing him either by reasoning or by observation; that is, either you wish to convince him by arguments, or else to turn his attention to himself, as is done with a man distracted, or one suffering mental derangement. The second is possible, but not the first. Whoever denies all principles, that of contradiction included, makes all argument impossible; in vain then will you reason with him. Let us see.
You think, one may say to him, at least you so assert, when you admit the principle I think. True. Then you must also admit the principle of contradiction. Why so? Because otherwise you could think and not think at the same time. Very well. But then you destroy your own thought. How? Is it not true that you think? Certainly. According to yourself it is possible that at the same time you do not think. I agree with you. Therefore, you destroy your thought; for if you do not think, the I think is destroyed, and, as all this is simultaneous, you destroy your own thought.
Not at all. What I object to in your system is that you suppose true the very thing which I deny, and so fall into the sophism named by logicians petitio principii. By the very fact of my denying the principle of contradiction, I deny that not-being destroys being, and that being destroys not-being; consequently, I do not admit that the I do not think destroys the I think. When you argue against me in this way, you suppose the very point in question, and attack me with principles which I do not admit. In your system, in which being destroys not-being, and vice versa, it is certain that to think, and not think, are incompatible; but on my principles, it is a very simple thing; since, according to them, it is not impossible for the same thing to be and not be at the same time, when I do not think, I do not cease to think. This is indeed absurd, but not illogical; deny the principle, and the deduction is necessary. And if it be said that in such a case he cannot reason, as he just has reasoned, he may reply that neither can his adversaries reason; or, if you choose, he sees no difficulty in their both reasoning and not reasoning.
Observation is the only means of bringing back one who has thus strayed away; such a one has departed from reason, and cannot be brought back to it by means of reason. Observations directed to him must be more of a call, a sort of alarm to arouse reason, not a combination to re-construct it: he is as a man asleep, or one in a swoon, and we must call him, and shake him, in order to arouse him; we must not dispute with him as with an adversary.(19)
CHAPTER XX.
TRUE SENSE OF THE PRINCIPLE OF CONTRADICTION.—KANT'S OPINION.
189. Before examining the value of the principle of contradiction as a basis for our cognitions, it will be well to fix