74. It is worthy of notice, that of the sensitive faculties, some would always be intuitive, that is, would always refer to an external object, if reflection did not accompany them; whilst others would never be intuitive, not even if separated from reflection, or unaccompanied by those which are by their nature intuitive. To the former class belong the representative faculties, properly so called, that is, those which affect the sensitive subject by presenting to it a form, the real or apparent image of an object. Such are those of sight and of touch, which can neither exist nor be conceived without this representation. Other sensations, on the contrary, offer no form to the sensitive subject; they are simple affections of the subject, although they proceed from an external cause; if we refer them to objects, this we do by reflection; and when this warns us that we have in attributing to the object not only the principle of causality, but also the sensation in itself, carried the reference too far, we easily recognize the illusion, and lay it aside. This does not occur in representative sensations; no one, no matter how great efforts he may make, will ever be able to persuade himself that beyond himself there is nothing real, nothing resembling the sensible representation in which objects are presented as extended.
75. When we say that some sensations would not be intuitive were they not accompanied by reflection, we do not mean to say that man refers them to an object, after explicit reflection, for we cannot forget what we have already said when explaining at length the instinctive way in which our faculties develop themselves prior to all reflection, in their relations with the corporeal world; but only that no necessary relation to an object as represented can be discovered in these sensations considered in themselves, and in perfect isolation; and that, probably, if a confused reflection be not mingled with the instinct which makes us render them objective, there at least enters some influence of other sensations, which are by their proper object representative.
[CHAPTER XI.]
TWO COGNITIONS: INTUITIVE AND DISCURSIVE.
76. Now that I have explained sensible, I pass to intellectual intuition. There are two modes of knowing; the one is intuitive, the other discursive. Intuitive cognition is that in which the object is presented to the understanding, such as it is, and upon which the perceptive faculty has to exercise no function but that of contemplation; it is therefore called intuition, from intueri, to see.
77. This intuition may take place in two ways. It may either present the object itself to the perceptive faculty, and unite them without any intermediacy; or by the intervention of an idea or representation, capable of putting the perceptive faculty in action, so that it may, without the necessity of combination, see the object in this representation. The first requires the object perceived to be intelligible by itself, since otherwise there could be no union of the object understood with the subject understanding; the second needs a representation to supply the place of the object, and consequently it is not indispensable that this should be immediately intelligible.[9]
78. Discursive cognition is that in which the understanding does not have the object itself present, but forms it itself, so to speak, by uniting in one whole conception several partial conceptions, whose connection in one subject it has found out by ratiocination.