226. Although in the present order these functions depend on certain conditions to which bodies are subject, considered in themselves, inasmuch as they are a modification of the soul, they have no essential relation to the corporeal world. It would therefore seem contrary to the principles of sound philosophy to say, that the soul separated from the body could not experience affections similar to those it has in this life. If this is not repugnant to the soul in its separate existence, why should it be so to other spirits?
The sensitive faculties are a sort of inferior order of perception. We see them in beings united to bodies, but they are not exercised immediately by a bodily organ. So far from contradicting simplicity, they require it; and therefore we have seen[58] that matter is incapable of sensation. Many grave philosophers are of opinion that the causality of bodies with respect to sensations, is only occasional. This opinion is founded on the difficulty of explaining how a composite being can produce affections of any kind in a simple being. Instead of a repugnance between simplicity and the sensitive faculties, there is, on the contrary, a necessary connection. No composite being can be sensitive.
227. Perhaps it may now be thought that there is no longer any doubt of the possibility of sensation independently of the bodily organs; and that to hold the contrary, it would be necessary to maintain that God can not produce immediately that which he produces by means of second causes. The observations which we have made may seem to have exhausted the matter, but if we reflect on it, we shall find that we have scarce entered on it.
It must not be forgotten that we are examining the possibility of sensitive faculties, in relation to one attribute only, that of simplicity. This greatly limits the question, as it leaves it to be solved under one aspect only. Simplicity is a negative property. When we say that any thing is simple, we deny that it has parts, but we affirm none of its properties; we say what it is not, not what it is. Therefore, in maintaining that sensitive faculties are not repugnant to a pure spirit, we ought to restrict the proposition; we should express our meaning more exactly, if instead of saying "sensitive faculties are not repugnant to a pure spirit," we should say, "sensitive faculties are not repugnant to the simplicity of a pure spirit."
228. This last observation seems to me to present the question in its true point of view. Any other expression of it seems only to confuse ideas and raise problems which we have not sufficient data to solve. In fact, how do we know but what the repugnance which does not exist between sensibility and simplicity, may exist between sensibility and some attribute which we know nothing about? This argument is not valid for the human soul, because we already know that the soul is capable of sensing; but it is valid for other spirits, whose essence is unknown to us, and the character of whose perceptive faculties experience has not discovered to us.
229. One of the distinctive marks of sensitive perception is the reference to individual objects, not in what concerns their essence, but inasmuch as they are arranged in a certain order, the variations of which do not affect their internal nature. Extension itself, which both instinct and reflection teach us to regard as objective, is rather a result of the relations of the beings which form the composite extended object, than those beings themselves. The sensitive faculties are the lowest grade in the order of perception. Their sole function is to make known to their possessor a certain arrangement of external objects, but they teach him nothing concerning the nature of those objects. Pure spirits are a grade higher in the scale of perceptive beings, and one of the characteristics of intelligence is, that it penetrates to the inward nature of things. Therefore it might easily happen that the sensible faculties are repugnant to intelligences of a higher order than ours, not by reason of their simplicity, but on account of the different manner of their perception.
230. Reasoning by analogy from what takes place within ourselves, we are confirmed in this opinion. Sensible representations are often powerful auxiliaries to purely intellectual perception; but they just as often embarrass and confuse it. In meditating on very abstract matters sensible representations are a hinderance to the understanding, from which we should be glad to free ourselves. Every one has experienced this to be so. They are like shadows which come between the eye of the intellect and the object: the necessity of continually removing them delays and weakens our perception. Thus, we propose, for example, to think of causality. No sensible representation should find place in this idea in the abstract, yet in spite of all our efforts the representation haunts us. At one time it is the word causality, written or spoken; at another, the image of a man doing something, or of any other agent. The sensible representation is always in our way, and we cannot free ourselves from its presence. The understanding is forced to repeat continually to itself, "This is not the idea of causality; it is only an image, a comparison, an expression;" in order to defend itself against illusions, which would make it confound the particular with the universal, the contingent with the necessary, the phenomenal with the real.
231. We must conclude from this that a repugnance of sensitive faculties to the nature of a pure spirit, might proceed from the character of its intelligence, which by reason of its perfection rejects the duality of perception which exists in us. The object of the understanding is the essence of the thing understood, quidditas, as the scholastics called it. Sensible representations tell us nothing of this essence. They offer only one aspect of things, and even this is limited to the perception of extension; for as regards the other sensations, they are a subjective fact which instinct and reason teach us to attribute to external causes, rather than a perception of the real disposition of things.
232. This suggests another observation which supports the conjecture that the elevation of intelligence above a certain degree makes it incompatible with sensitive faculties. Sensations would tell us nothing even of this aspect and disposition of things if they did not have extension for their basis. To what should we reduce the corporeal world if we supposed it unextended? Since extension, as we have shown,[59] although the basis of some sensations, is not the direct and immediate object of sensation; that which in the sensitive faculties makes us perceive something of the reality of objects, is not strictly sensible. Therefore, if it is the character of intellectual perception to know the reality of the object, the more elevated an intelligence is the farther it will be from sensation, and there may be a subject in which intellectual faculties are incompatible with sensitive faculties.
233. We shall better understand the force of this observation by casting a glance at the scale of beings, and noting the difference in them in proportion to their perfection. The isolation of a being is a mark of its imperfection. The lowest idea of an object is that which we form when we conceive it absolutely limited to existence, completely inert, without either internal or external activity. A stone has existence and a determinate form; it is what it was made, and nothing more; it preserves the form which was given to it, but it has no activity to communicate with other beings, no consciousness of what it is; in all its relations it is passive; it receives but cannot give.