But we must own that the amount of freedom which is left to us after strictly complying with the principle of the conservation of energy is rather limited. For, even if this law does not exert a necessitating influence over the course of our ideas, it will at least determine our movements. Our inner life will still depend upon ourselves up to a certain point; but, to an outside observer, there will be nothing to distinguish our activity from absolute automatism. We are thus led to inquire whether the very extension of the principle of the conservation of energy to all the bodies in nature does not itself involve some psychological theory, and whether the scientist who did not possess a priori any prejudice against human freedom would think of setting up this principle as a universal law.
It implies that a system can return to its original state. Neglects duration, hence inapplicable to living beings and conscious states.
We must not overrate the part played by the principle of the conservation of energy in the history of the natural sciences. In its present form it marks a certain phase in the evolution of certain sciences; but it has not been the governing factor in this evolution and we should be wrong in making it the indispensable postulate of all scientific research. Certainly, every mathematical operation which we carry out on a given quantity implies the permanence of this quantity throughout the course of the operation, in whatever way we may split it up. In other words, what is given is given, what is not given is not given, and in whatever order we add up the same terms we shall get the same result. Science will for ever remain subject to this law, which is nothing but the law of non-contradiction; but this law does not involve any special hypothesis as to the nature of what we ought to take as given, or what will remain constant. No doubt it informs us that something cannot come from nothing; but experience alone will tell us which aspects or functions of reality must count for something, and which for nothing, from the point of view of positive science. In short, in order to foresee the state of a determinate system at a determinate moment, it is absolutely necessary that something should persist as a constant quantity throughout a series of combinations; but it belongs to experience to decide as to the nature of this something, and especially to let us know whether it is found in all possible systems, whether, in other words, all possible systems lend themselves to our calculations. It is not certain that all the physicists before Leibniz believed, like Descartes, in the conservation of a fixed quantity of motion in the universe: were their discoveries less valuable on this account or their researches less successful? Even when Leibniz had substituted for this principle that of the conservation of vis viva, it was not possible to regard the law as quite general, since it admitted of an obvious exception in the case of the direct impact of two inelastic bodies. Thus science has done for a very long time without a universal conservative principle. In its present form, and since the development of the mechanical theory of heat, the principle of the conservation of energy certainly seems to apply to the whole range of physico-chemical phenomena. But no one can tell whether the study of physiological phenomena in general, and of nervous phenomena in particular, will not reveal to us, besides the vis viva or kinetic energy of which Leibniz spoke, and the potential energy which was a later and necessary adjunct, some new kind of energy which may differ from the other two by rebelling against calculation. Physical science would not thereby lose any of its exactitude or geometrical rigour, as has lately been asserted: only it would be realized that conservative systems are not the only systems possible, and even, perhaps, that in the whole of concrete reality each of these systems plays the same part as the chemist's atom in bodies and their combinations. Let us note that the most radical of mechanical theories is that which makes consciousness an epiphenomenon which, in given circumstances, may supervene on certain molecular movements. But, if molecular movement can create sensation out of a zero of consciousness, why should not consciousness in its turn create movement either out of a zero of kinetic and potential energy, or by making use of this energy in its own way? Let us also note that the law of the conservation of energy can only be intelligibly applied to a system of which the points, after moving, can return to their former positions. This return is at least conceived of as possible, and it is supposed that under these conditions nothing would be changed in the original state of the system as a whole or of its elements. In short, time cannot bite into it; and the instinctive, though vague, belief of mankind in the conservation of a fixed quantity of matter, a fixed quantity of energy, perhaps has its root in the very fact that inert matter does not seem to endure or to preserve any trace of past time. But this is not the case in the realm of life. Here duration certainly seems to act like a cause, and the idea of putting things back in their place at the end of a certain time involves a kind of absurdity, since such a turning backwards has never been accomplished in the case of a living being. But let us admit that the absurdity is a mere appearance, and that the impossibility for living beings to come back to the past is simply owing to the fact that the physico-chemical phenomena which take place in living bodies, being infinitely complex, have no chance of ever occurring again all at the same time: at least it will be granted to us that the hypothesis of a turning backwards is almost meaningless in the sphere of conscious states. A sensation, by the mere fact of being prolonged, is altered to the point of becoming unbearable. The same does not here remain the same, but is reinforced and swollen by the whole of its past. In short, while the material point, as mechanics understands it, remains in an eternal present, the past is a reality perhaps for living bodies, and certainly for conscious beings. While past time is neither a gain nor a loss for a system assumed to be conservative, it may be a gain for the living being, and it is indisputably one for the conscious being. Such being the case, is there not much to be said for the hypothesis of a conscious force or free will, which, subject to the action of time and storing up duration, may thereby escape the law of the conservation of energy?
The idea of the universality of conservation depends on confusion between concrete duration and abstract time.
In truth, it is not a wish to meet the requirements of positive science, but rather a psychological mistake which has caused this abstract principle of mechanics to be set up as a universal law. As we are not accustomed to observe ourselves directly, but perceive ourselves through forms borrowed from the external world, we are led to believe that real duration, the duration lived by consciousness, is the same as the duration which glides over the inert atoms without penetrating and altering them. Hence it is that we do not see any absurdity in putting things back in their place after a lapse of time, in supposing the same motives acting afresh on the same persons, and in concluding that these causes would again produce the same effect. That such an hypothesis has no real meaning is what we shall prove later on. For the present let us simply show that, if once we enter upon this path, we are of course led to set up the principle of the conservation of energy as a universal law. For we have thereby got rid of just that difference between the outer and the inner world which a close examination shows to be the main one: we have identified true duration with apparent duration. After this it would be absurd to consider time, even our time, as a cause of gain or loss, as a concrete reality, or a force in its own way. Thus, while we ought only to say (if we kept aloof from all presuppositions concerning free will) that the law of the conservation of energy governs physical phenomena and may, one day, be extended to all phenomena if psychological facts also prove favourable to it, we go far beyond this, and, under the influence of a metaphysical prepossession, we lay down the principle of the conservation of energy as a law which should govern all phenomena whatever, or must be supposed to do so until psychological facts have actually spoken against it. Science, properly so called, has therefore nothing to do with all this. We are simply confronted with a confusion between concrete duration and abstract time, two very different things. In a word, the so-called physical determinism is reducible at bottom to a psychological determinism, and it is this latter doctrine, as we hinted at first, that we have to examine.
Psychological determinism depends on associationist conception of mind.
Psychological determinism, in its latest and most precise shape, implies an associationist conception of mind. The existing state of consciousness is first thought of as necessitated by the preceding states, but it is soon realized that this cannot be a geometrical necessity, such as that which connects a resultant, for example, with its components. For between successive conscious states there exists a difference of quality which will always frustrate any attempt to deduce any one of them a priori from its predecessors. So experience is appealed to, with the object of showing that the transition from one psychic state to another can always be explained by some simple reason, the second obeying as it were the call of the first. Experience really does show this: and, as for ourselves, we shall willingly admit that there always is some relation between the existing state of consciousness and any new state to which consciousness passes. But is this relation, which explains the transition, the cause of it?
The series of associations may be merely an ex post facto attempt to account for a new idea.
May we here give an account of what we have personally observed? In resuming a conversation which had been interrupted for a few moments we have happened to notice that both we ourselves and our friend were thinking of some new object at the same time.—The reason is, it will be said, that each has followed up for his own part the natural development of the idea at which the conversation had stopped: the same series of associations has been formed on both sides.—No doubt this interpretation holds good in a fairly large number of cases; careful inquiry, however, has led us to an unexpected result. It is a fact that the two speakers do connect the new subject of conversation with the former one: they will even point out the intervening ideas; but, curiously enough, they will not always connect the new idea, which they have both reached, with the same point of the preceding conversation, and the two series of intervening associations may be quite different. What are we to conclude from this, if not that this common idea is due to an unknown cause—perhaps to some physical influence—and that, in order to justify its emergence, it has called forth a series of antecedents which explain it and which seem to be its cause, but are really its effect?
Illustration from hypnotic suggestion.