Moreover, there is one essential characteristic of the impersonal forces which would be inexplicable under this hypothesis: this is their communicability. The forces of nature have always been thought of as capable of passing from one object to another, of mixing, combining and transforming themselves into one another. It is even this property which gives them their value as an explanation, for it is through this that effects can be connected with their causes without a break of continuity. Now the self has just the opposite characteristic: it is incommunicable. It cannot change its material substratum or spread from one to another; it spreads out in metaphor only. So the way in which it decides and executes its decisions could never have suggested the idea of an energy which communicates itself and which can even confound itself with others and, through these combinations and mixings, give rise to new effects.
Therefore, the idea of force, as implied in the conception of the causal relation, must present a double character. In the first place, it can come only from our internal experience; the only forces which we can directly learn about are necessarily moral forces. But, at the same time, they must be impersonal, for the notion of an impersonal power was the first to be constituted. Now the only ones which satisfy these two conditions are those coming from life together: they are collective forces. In fact, these are, on the one hand, entirely psychical; they are made up exclusively of objectified ideas and sentiments. But, on the other hand, they are impersonal by definition, for they are the product of a co-operation. Being the work of all, they are not the possession of anybody in particular. They are so slightly attached to the personalities of the subjects in whom they reside that they are never fixed there. Just as they enter them from without, they are also always ready to leave them. Of themselves, they tend to spread further and further and to invade ever new domains: we know that there are none more contagious, and consequently more communicable. Of course physical forces have the same property, but we cannot know this directly; we cannot even become acquainted with them as such, for they are outside us. When I throw myself against an obstacle, I have a sensation of hindrance and trouble; but the force causing this sensation is not in me, but in the obstacle, and is consequently outside the circle of my perception. We perceive its effects, but we cannot reach the cause itself. It is otherwise with social forces: they are a part of our internal life, as we know, more than the products of their action; we see them acting. The force isolating the sacred being and holding profane beings at a distance is not really in this being; it lives in the minds of the believers. So they perceive it at the very moment when it is acting upon their wills, to inhibit certain movements or command others. In a word, this constraining and necessitating action, which escapes us when coming from an external object, is readily perceptible here because everything is inside us. Of course we do not always interpret it in an adequate manner, but at least we cannot fail to be conscious of it.
Moreover, the idea of force bears the mark of its origin in an apparent way. In fact, it implies the idea of power which, in its turn, does not come without those of ascendancy, mastership and domination, and their corollaries, dependence and subordination; now the relations expressed by all these ideas are eminently social. It is society which classifies beings into superiors and inferiors, into commanding masters and obeying servants; it is society which confers upon the former the singular property which makes the command efficacious and which makes power. So everything tends to prove that the first powers of which the human mind had any idea were those which societies have established in organizing themselves: it is in their image that the powers of the physical world have been conceived. Also, men have never succeeded in imagining themselves as forces mistress over the bodies in which they reside, except by introducing concepts taken from social life. In fact, these must be distinguished from their physical doubles and must be attributed a dignity superior to that of these latter; in a word, they must think of themselves as souls. As a matter of fact, men have always given the form of souls to the forces which they believe that they are. But we know that the soul is quite another thing from a name given to the abstract faculty of moving, thinking and feeling; before all, it is a religious principle, a particular aspect of the collective force. In fine, a man feels that he has a soul, and consequently a force, because he is a social being. Though an animal moves its members just as we do, and though it has the same power as we over its muscles, nothing authorizes us to suppose that it is conscious of itself as an active and efficacious cause. This is because it does not have, or, to speak more exactly, does not attribute to itself a soul. But if it does not attribute a soul to itself, it is because it does not participate in a social life comparable to that of men. Among animals, there is nothing resembling a civilization.[1188]
But the notion of force is not all of the principle of causality. This consists in a judgment stating that every force develops in a definite manner, and that the state in which it is at each particular moment of its existence predetermines the next state. The former is called cause, the latter, effect, and the causal judgment affirms the existence of a necessary connection between these two moments for every force. The mind posits this connection before having any proofs of it, under the empire of a sort of constraint from which it cannot free itself; it postulates it, as they say, a priori.
Empiricism has never succeeded in accounting for this apriorism and necessity. Philosophers of this school have never been able to explain how an association of ideas, reinforced by habit, could produce more than an expectation or a stronger or weaker predisposition on the part of ideas to appear in a determined order. But the principle of causality has quite another character. It is not merely an imminent tendency of our thought to take certain forms; it is an external norm, superior to the flow of our representations, which it dominates and rules imperatively. It is invested with an authority which binds the mind and surpasses it, which is as much as to say that the mind is not its artisan. In this connection, it is useless to substitute hereditary habit for individual habit, for habit does not change its nature by lasting longer than one man's life; it is merely stronger. An instinct is not a rule.
The rites which we have been studying allow us to catch a glimpse of another source of this authority, which, up to the present, has scarcely been suspected. Let us bear in mind how the law of causality, which the imitative rites put into practice, was born. Being filled with one single preoccupation, the group assembles: if the species whose name it bears does not reproduce, it is a matter of concern to the whole clan. The common sentiment thus animating all the members is outwardly expressed by certain gestures, which are always the same in the same circumstances, and after the ceremony has been performed, it happens, for the reasons set forth, that the desired result seems obtained. So an association arises between the idea of this result and that of the gestures preceding it; and this association does not vary from one subject to another; it is the same for all the participators in the rite, since it is the product of a collective experience. However, if no other factor intervened, it would produce only a collective expectation; after the imitative gestures had been accomplished, everybody would await the subsequent appearance of the desired event, with more or less confidence; an imperative rule of thought could never be established by this. But since a social interest of the greatest importance is at stake, society cannot allow things to follow their own course at the whim of circumstances; it intervenes actively in such a way as to regulate their march in conformity with its needs. So it demands that this ceremony, which it cannot do without, be repeated every time that it is necessary, and consequently, that the movements, a condition of its success, be executed regularly: it imposes them as an obligation. Now they imply a certain definite state of mind which, in return, participates in this same obligatory character. To prescribe that one must imitate an animal or plant to make them reproduce, is equivalent to stating it as an axiom which is above all doubt, that like produces like. Opinion cannot allow men to deny this principle in theory without also allowing them to violate it in their conduct. So society imposes it, along with the practices which are derived from it, and thus the ritual precept is doubled by a logical precept which is only the intellectual aspect of the former. The authority of each is derived from the same source: society. The respect which this inspires is communicated to the ways of thought to which it attaches a value, just as much as to ways of action. So a man cannot set aside either the ones or the others without hurling himself against public opinion. This is why the former require the adherence of the intelligence before examination, just as the latter require the submission of the will.
From this example, we can show once more how the sociological theory of the idea of causality, and of the categories in general, sets aside the classical doctrines on the question, while conciliating them. Together with apriorism, it maintains the prejudicial and necessary character of the causal relation; but it does not limit itself to affirming this; it accounts for it, yet without making it vanish under the pretext of explaining it, as empiricism does. On the other hand, there is no question of denying the part due to individual experience. There can be no doubt that by himself, the individual observes the regular succession of phenomena and thus acquires a certain feeling of regularity. But this feeling is not the category of causality. The former is individual, subjective, incommunicable; we make it ourselves, out of our own personal observations. The second is the work of the group, and is given to us ready-made. It is a frame-work in which our empirical ascertainments arrange themselves and which enables us to think of them, that is to say, to see them from a point of view which makes it possible for us to understand one another in regard to them. Of course, if this frame can be applied to the contents, that shows that it is not out of relation with the matter which it contains; but it is not to be confused with this. It surpasses it and dominates it. This is because it is of a different origin. It is not a mere summary of individual experiences; before all else, it is made to fulfil the exigencies of life in common.
In fine, the error of empiricism has been to regard the causal bond as merely an intellectual construction of speculative thought and the product of a more or less methodical generalization. Now, by itself, pure speculation can give birth only to provisional, hypothetical and more or less plausible views, but ones which must always be regarded with suspicion, for we can never be sure that some new observation in the future will not invalidate them. An axiom which the mind accepts and must accept, without control and without reservation, could never come from this source. Only the necessities of action, and especially of collective action, can and must express themselves in categorical formulæ, which are peremptory and short, and admit of no contradiction, for collective movements are possible only on condition of being in concert and, therefore, regulated and definite. They do not allow of any fumbling, the source of anarchy; by themselves, they tend towards an organization which, when once established, imposes itself upon individuals. And as action cannot go beyond intelligence, it frequently happens that the latter is drawn into the same way and accepts without discussion the theoretical postulates demanded by action. The imperatives of thought are probably only another side of the imperatives of action.
It is to be borne in mind, moreover, that we have never dreamed of offering the preceding observations as a complete theory of the concept of causality. The question is too complex to be resolved thus. The principle of causality has been understood differently in different times and places; in a single society, it varies with the social environment and the kingdoms of nature to which it is applied.[1189] So it would be impossible to determine with sufficient precision the causes and conditions upon which it depends, after a consideration of only one of the forms which it has presented during the course of history. The views which we have set forth should be regarded as mere indications, which must be controlled and completed. However, as the causal law which we have been considering is certainly one of the most primitive which exists, and as it has played a considerable part in the development of human thought and industry, it is a privileged experiment, so we may presume that the remarks of which it has been the occasion may be generalized to a certain degree.