Evolution

by F. B. Jevons

We began this chapter with an expression of our full adhesion to the view which insists upon the uniformity, not merely of nature, but also of human nature. We rejected the idea that there is no science of man, and has been no evolution of mind, as a patent absurdity, and a violent contradiction of admitted facts. Any theory of evolution and any definition of science which fails to comprehend human nature is thereby condemned as inadequate and inaccurate. For those, then, who with us accept the continuity and uniformity between nature and man there will be no difficulty in arguing from the one to the other: which of the two we shall start from will depend mainly upon circumstances, upon which is the more accessible in any particular inquiry, and which is likely to afford the best "take-off." In the present case the action of inanimate objects upon one another can be accounted for on either hypothesis, i.e. that such action is willed by some superior power or that it is necessitated by some previous action, which is necessitated by some other previous action, and so on for ever, without ever reaching any original or originating necessity. Both hypotheses will fit all the facts of all the physical sciences; both are hypotheses; and science can do and does do without either one or the other. Nor does our observation of the observed facts of nature enable us to say, with regard to any actual fact of this kind, either that it could or that it could not have happened otherwise than it did. In fine, as long as we confine ourselves to the subject-matter of the physical sciences, as long as we start in this case from nature, we cannot find anything to disturb the equal balance of the two hypotheses, which are two hypotheses and nothing more. But when we turn from nature to human nature, when we consult our own experience of our own actions, the case is notoriously different. Our experience in that case is that of two or more suggested and possible actions we are free to choose whichever we will; and our memory of past acts of choice testifies that though we actually chose one particular course, we might have abstained from it in favour of some other alternative. Here, too, as in the case of purely physical causation, the fact that a thing happened is proof conclusive that, in accordance with the law of universal causation, the conditions necessary to its occurrence were fulfilled; but it constitutes no proof or probability that the conditions were bound to be fulfilled. The fact that we chose to act in a certain way does not in the least convince us that we were bound to choose that action and that action alone. On the contrary, our memory is clear and our conviction is certain that our choice was free. In the physical and the spiritual spheres alike it is true that, when all the conditions requisite for a given effect are combined, the result must ensue. And in both spheres it is equally true that until the conditions are effectively combined no such necessity exists. In the case of our own actions we are directly and immediately conscious of the fact that it is our own will which effects this combination. For us, therefore, who hold, with Professor Huxley, that the uniformity and continuity of nature with human nature is essential to any rational and scientific view of the universe and to every comprehensive theory of evolution, it is natural to interpret physical by spiritual causation. We know from direct and personal experience of certain cases of causation that, though a particular effect necessarily ensued from a certain combination of conditions, the conditions might have been combined differently and with a different result. There is, therefore, nothing unreasonable in the inference that with regard to the events in nature the conditions which produced them might have combined differently and with different results; and that the determining factor was a will (not our own) conscious of its own freedom.

Thus far, then, the case stands thus, that in the observed facts of nature there is nothing to incline the balance in favour either of Necessity or Free-will; and that if those facts constituted the whole of our experience we should have no reason to believe the one rather than the other. But when we turn to the consideration of events of which we are the cause, we know that our contribution to the sum of conditions on which the event depends is a free-will offering which we make or decline to make as we like. That consideration would not in itself be sufficient to warrant us in inferring a similar absence of necessity in the combination of the conditions which produce natural events. If, for instance, we had reason to believe or evidence to show an absolute chasm between nature and human nature, an impossibility of their being subject to any common laws or conceptions; or if, like primitive man or the savage, we had not the accumulated observations of science to demonstrate the truth of evolution and the law of continuity—then we should have no reason or little reason, as the case might be, for interpreting nature's action and human action by one another.

The savage, as is well known, does, without any scientific authority whatever, assume straight off an entire uniformity of nature with human nature. He jumps at conclusions: he takes it for granted that everything which moves has a will of its own, like himself. But though the savage shares with the savant the impulse to believe in an essential continuity binding together man and nature, that impulse is about all they have in common. In the savage it expresses itself in an absolute identification, entirely ignoring all differences, between the two: the tree or the river has to be a conscious, rational creature, though its behaviour bears more difference from than resemblance to that of a human being. In the savant, the same impulse is trained to fertility by being constantly subjected to the guidance of observed facts: man as an animal organism is subject to the same physiological laws as other similar organisms; as an organic compound, to the same chemical changes; as a body possessing inertia, to the same physical laws. The savant's belief, however, in the continuity of nature and human nature is consistent with or rather implies points of difference between the two; e.g. man possesses a consciousness which the river does not, man is, the river is not, a conscious cause. Great though these differences be, still they are not in the eyes of science and from the point of view of evolution great enough to constitute a breach of continuity, for human actions are with the growth of science increasingly seen to be part of the uniformity of nature: the human cause only produces its effect provided that all the requisite conditions are forthcoming. Indeed, there is a danger, in some tendencies of modern thought, of ignoring the differences and of confounding continuity with identity. The distinction between the animate and the inanimate, which was hardly reached by the savage, is in danger of being overlooked by the modern materialist—an error which would be paralleled in religion by a relapse from monotheism into nature-worship. And as in the pathology of religion there is a constant tendency to substitute for religious faith a trust in the automatic efficacy of rites and ceremonies, which is a falling away into mere magic, so in metaphysic there is a tendency, in the name of science falsely invoked, to substitute for the actions of agents consciously free the operation of an automatic and magical necessity. Freedom of the will is constantly taken, or rather mistaken, both by its supporters and opponents, to mean the power of acting without a motive, and to imply that from identically the same combination of conditions one result can ensue at one time and quite a different one at another; and freedom of the will in this sense, and with this implication, is rightly rejected as inconsistent with the uniformity of nature. Freedom, however, means not the absence of motive, but the presence of more motives than one, for where there is no alternative there is no freedom, and where there is an alternative there is a choice between two things. The fact that conscious action is always action with a motive has nothing in it repugnant to the uniformity of nature, unless uniformity of nature is arbitrarily assumed to be identical with necessity. Nor has the uniformity of nature, i.e. the fact that the same action issues from the same combination of conditions, anything in it inconsistent with the freedom of the will, unless the occurrence of an event proves that it was bound to occur. The laws of science—whether physical science or mental and moral science—are hypothetical statements: if the love of gain predominates in men, then all the consequences predicted by the science of Political Economy will ensue. But this proves neither that the love of gain must nor even that it does prevail. The uniformity which marks the actions of men as often as this motive prevails is sufficient for the purposes of science, and is consistent with the freedom of the will; it does not imply that men act without a motive, nor that the same conditions produce now one effect and now another. Until the conditions which are necessary for the production of a physical event are effectively combined, physical science knows no necessity to make them combine in that particular way; if they combine in some other way, and with some other result, that combination will equally illustrate the truth of science (which says, if A then B, if A₁ then B₁), and the result will equally accord with the uniformity of nature. The same considerations apply to human nature, and if applied will be found consistent with the freedom of the will. Until the mind is made up, i.e. so long as there are alternative courses open to it, the man is free, just in the same way as in physical science, until the combination of conditions is effected, the result may or may not follow. If one alternative is adopted one set of consequences will ensue, if another, another; but whichever is adopted the results will be in accordance with the uniformity of nature, the law of cause and effect will not have been violated, the mind will not have acted without a motive, or under the influence of necessity. In fine, the universality of the law of causation lies in the fact that, however the conditions combine, each combination can only produce its peculiar effect; and whatever effect occurs can be the result only of its appropriate conditions. To say with the necessitarian that, unless at the beginning of things the course of events was unalterably fixed once and for ever, there can be no science, is to deny the universality of the laws of science, to maintain that they are true only of one particular succession of events, and would not be true of any other. In point of fact, however, the laws of science, by their hypothetical form, are adapted to cope with what is at least as striking as the uniformity of nature, that is, the diversity of nature: they apply not merely to one, but to all possible combinations of circumstances. In what way a body will move depends upon the conditions at work; but Science is not such a maimed and crippled thing that she refuses to consider its motion until she has been assured that, of the various conceivable conditions that might be brought to bear on the body, only one can, as a matter of fact, be brought to bear. On the contrary, the universality of her laws lies in the fact that they apply to all possible combinations, not merely to combination A producing B, but to A₁ producing B₁, A₂ producing B₂, and so on. The origin of all terrestrial life may be traced back, let us say, to the fortuitous combination of chemicals which constituted the first speck of protoplasm; and sundry important consequences can be shown by science to have flowed from that fortuitous concurrence. The origin of any particular species may be traced back to the accidental appearance of a sport or variety which happened to be better adapted to the environment than the parent forms were.

But, if these accidental and fortuitous occurrences had not taken place, the subsequent course of things upon earth, though there might have been no life, would still have been just as much in accordance with the uniformity (and the diversity) of nature, and equally amenable to scientific explanation. The theory that the first speck of protoplasm or the ancestral variety of a species was bound by a metaphysical necessity to occur just when and where it did, is of no use to science: if A had not happened, A₁ or A₂ or A₃ would have done, and the resulting B or B₁ or B₂ or B₃ would have been equally in accordance with the uniformity of nature and equally explicable by science.

If, then, in the physical world neither science nor the uniformity of nature requires us to believe in necessity, there is no antecedent presumption that necessity must be the law of the spiritual world: we may examine the facts of our own inner experience without prejudice. What the freedom of the will implies is that the mind has present to it more alternatives or motives than one, and that they are real alternatives and real motives, i.e. motives which may really in this particular case influence action, alternatives any one of which may be adopted in this case. The circumstances or conditions in which a man makes up his mind are, until he has made up his mind, so to speak, held in solution, and may be precipitated this way or that at his choice, or not precipitated at all, unless he chooses. The fact that in the same circumstances the same result ensues is no argument against the freedom of the will, if it be remembered that the will is itself one of the circumstances which contribute to the result, just as the mass of a body, as well as the force applied to it, helps to determine its velocity. The statement of the case then becomes this: if all the circumstances of the case be the same, and the will be the same, the consequences (i.e. the determination of the will) also will be the same. But the necessitarian position requires the statement that if all the circumstances be the same, then without any further proviso the will is determined by the circumstances; or, to put it another way, that the will does not in any way contribute to the result, which is just as though we were to say that the mass of a body had nothing to do with its velocity. But if the will does contribute to the result, i.e. to the determination of itself, it is in part self-determining.

That there must be some circumstances present, if there is to be any self-determination on the part of the will, we have already admitted; the freedom of the will implies the presence of more alternatives or motives than one—and we always have the alternative of acting or abstaining from action. But this admission only limits the powers of the will; it does not lessen its liberty. The mind can only choose between the alternatives offered to it; but as long as it has real alternatives it is free. That there must be definite circumstances if there is to be any definite determination of the will is in accordance with the fact that a cause is not some one individual thing, but a sum of conditions, every one of which is necessary to the effect, and the absence of any one of which is enough to prevent the occurrence of the result. It is a vulgar error to single out some one of the conditions (e.g. the force acting on a body) and dub it the cause, to the neglect of all the other conditions (e.g. the body's mass) which are equally necessary to the effect. It is the error committed by the necessitarian who calls the circumstances the cause, in the case of a determination of the will, and neglects the part played by the will itself.

This point of view illustrates the untenability of another objection to the freedom of the will, viz. that it implies that under the same conditions different results can ensue, or, to put it in other words, that without any change in the conditions either this or that consequence may issue. Freedom of the will is thus alleged to be inconsistent with the uniformity of nature, with the law that a cause must produce its effect. The fallacy here obviously lies in assuming that, in a modification of the will, the circumstances by themselves constitute the cause, whereas in point of fact the cause consists of the sum of the conditions, i.e., in this case, of the circumstances and the will taken in combination. Alter any one of the conditions, and the effect will be changed—whether the condition which is changed be one of the circumstances or be the will, matters not. Conversely, if under the same circumstances a man acts one way one time and another another, the inference is not that the uniformity of nature has been violated, and that the same conditions produce different effects, but that one of the conditions was different; and as ex hypothesi the circumstances (i.e. all the conditions except the will) were in this case the same, it remains that the condition which was different in this case was the will.

Really, it is the theory of necessity which violates the uniformity of nature, for it requires us to believe that provided certain of the conditions (viz. all the circumstances except the will) are the same, then the result must be the same, no matter how much the remaining condition (the will) changes. We may, indeed, evade this conclusion by simply denying that the will is one of the conditions of its own modifications, and we may say that the wax contributes nothing to the form which it takes on when impressed by the seal. The truth is that if the will or the wax appears in the result, it must have been present and active as one of the conditions: it contributes to its own determination, and is in part self-determining.

If it be in accordance with the uniformity of nature and with our experience of what actually happens, that the circumstances should be the same and the will different on two different occasions, then the theory of necessity breaks down: if we can will and act differently under the same circumstances, we have all the freedom we want. But if—all the circumstances, save the will, being the same—the resulting modification or determination of the will is different, then the difference of result must be due to some difference in the conditions; all the conditions save one were ex hypothesi the same; the remaining condition, therefore, viz. the will, must have changed. What caused the change? Not the circumstances: one attempt to explode a barrel of gunpowder may resemble another in all the circumstances save one (the dampness of the powder), but the circumstances which remain the same (application of the spark, etc.) are not the cause of the difference in the remaining condition.

If, then, we do as a matter of fact at times under the same circumstances will different things, and if the circumstances are not the cause of the change of will, then the will changes itself, i.e. is self-determining, self-modifying. And, as we all know from experience, it determines itself at the moment of choice, not before. Until all the conditions requisite for the effect are combined, neither physical nor mental science requires us to assume that they must combine in this particular way—that the light must be applied to the powder because an explosion will take place if it is applied, that the motive of gain must be adopted because it will be gratified if it is obeyed.