Thilly, Frank. “Causality.” The Philosophical Review 16, no. 2 (1907): 117. https://doi.org/10.2307/2177467
IT has frequently been pointed out that many controversies are due to the fact that the disputants employ the fundamental terms in different senses. When there is no agreement concerning the basal notions used in a discussion, it will be impossible for the participants to reach the same conclusion. The way one interprets certain facts will frequently depend upon the conceptions or definitions which one has made one's starting point. I have tried to show in a paper on " The Theory of Interaction, “published in THE PHILOSOPHICAL REVIEW, that many thinkers really deduce their conclusions on the question of the relation between mind and body from their conception of causality, and that their results differ as their interpretations of this law differ. It seems that, in spite of all that has been written on this subject, there is no universal agreement as to what causality really means. Under these circumstances it does not seem to me out of place to consider this whole problem again. We shall attempt to answer three questions here: (I) What does the notion mean? (2) What is its origin? (3) What is its validity?
Hume started out with the idea that all our notions are derived from our sensations, that when we analyze our thoughts or ideas "we always find that they resolve themselves into such simple ideas as were copied from a precedent feeling or sentiment." This principle largely determined his conception of causality, for on this hypothesis there can be nothing in the idea because that is not derived from our perceptions. Now all we experience, when we call one event the effect or cause of another, is coexistence or succession. We do not see powers or forces operating between phenomena in the physical realm. "When we look about us towards external objects and consider the operation of causes, we are never able in a single instance, to discover any power or necessary connection; any quality which binds the effect to the cause, and renders the one an infallible consequence of the other. We only find that the one does actually in fact follow the other. The impulse of one billiard ball attended with motion in the second. This is the whole that appears to the outward senses. The mind feels no sentiment or inward impression from this succession of objects; consequently, there is not, in any single particular instance of cause and effect, anything which can suggest the idea of power or necessary connection."
Nor do we derive this notion from " reflection on the operation of our own minds." We are conscious that the motion of our body follows upon the command of our will, but we are not conscious of the energy by which the will performs this operation. In short, we never discover anything but one event following upon another; we never discover any power, all we see is one event following another, hence it is meaningless to talk about such a power. We see one event always conjoined with another, we therefore suppose there is some connection between them, some power in the one by which it infallibly produces the other and must always produce it. After a repetition of similar instances, "the mind is carried by habit, upon the appearance of the event, to expect its usual attendant, and to believe that it will exist. This connection, therefore, which we feel in the mind, this customary transition of the imagination from one object to its usual attendant, is the sentiment or impression from which we form the idea of power or necessary connection. Nothing farther is in the case. Contemplate the subject on all sides; you will never find any other origin of that idea. This is the sole difference between one instance, from which we can never receive the idea of connection, and a number of similar instances, by which it is suggested. The first time a man saw the communication of motion by impulse, as by the shock of two billiard balls, he could not pronounce that the one event was connected, but only that it was conjoined with the other. After he has observed several instances of this nature, he then pronounces them to be connected. What alteration has happened to give rise to this new idea of connection? Nothing but that he now feels these events to be connected in his imagination and can readily foretell the existence of one from the appearance of the other."
John Stuart Mill's view does not differ much from this. “The only notion of a cause," he says, "which the theory of induction requires, is such a notion as can be gained from experience. The law of causation ... is but the familiar truth, that invariability of succession is found by observation to obtain between every fact in nature and some other fact which has preceded it; independently of all considerations respecting the ultimate mode of production of phenomena, and of every other question regarding the nature of 'things in themselves.'" "When we define the cause of anything (in the only sense in which the present inquiry has any concern with causes) to be 'the antecedent which it invariably follows,' we do not use this phrase as exactly synonymous with 'the antecedent which it invariably has followed in our past experience.' . . . But it is necessary to our using the word cause, that we should believe not only that the antecedent always has been followed by the consequent, but that, as long as the present constitution of things endures, it always will be so.. . . This is what writers mean when they say that the notion of cause involves the idea of necessity. If there be any meaning which confessedly belongs to the term necessity, it is unconditionalness. That which is necessary, that which must be, means that which will be, whatever supposition we may make in regard to all other things. ... Invariable sequence, therefore, is not synonymous with causation, unless the sequence, besides being invariable, is unconditional. . .. We may define, therefore, the cause of a phenomenon, to be the antecedent, or the concurrence of antecedents, on which it is invariably and unconditionally consequent."
Hume and Mill agree that causality means regular temporal succession or coexistence, and they both also eliminate the idea of force or energy from the notion. Mill admits that we experience effort in our own voluntary action but sees no reason why we should read this experience into the physical world: that would be fetishism. Hume is somewhat vacillating on this point. After denying that we perceive such power or energy or force in our own minds, he finally admits, in a note, that we experience it and that it enters into the vulgar inaccurate idea of causality.
Many modern thinkers, however, introduce into the notion of causality the very idea which Hume and Mill and their followers reject as fetishism. Thus Erhardt, in an able work on metaphysics, makes the feeling of effort the very heart of the causal idea. According to him, we have an immediate perception firkin and Bewirken in ourselves in our feeling of effort. Indeed, by effecting (Bewirken), he says, I mean just what I experience in myself when I exert myself and produce a change in the inner and outer world. Of course, I do not know why this happens, Buti know that it happens. Wirken means what we have in this experience. A change produces another means that a sensation of effort is followed by an external effect. “We experience ourselves as willing and acting beings; willing and acting, however, are notions which already imply the idea of Bewirken, as has been pointed out. Hardly less certain is the fact that external objects produce certain effects; the sensations of resistance, e.g., which we experience in attempting to move a body show at once that this body possesses a certain power of action. True, the sensation itself is all that is directly given to us; at the same time, we perceive that this sensation arises when the object comes in contact with our body. We also know that the sensation does notaries without such contact, and that it always arises on occasion of the contact. Finally, our inner experience tells us that we do not ourselves voluntarily produce the sensation. Hence, we have to infer that the contact of the external object is the cause of our sensation, i.e., we experience the efficiency of the resisting body through our feeling of resistance. . .. Whatever the object may be in itself, so far as we know it through experience it is bound to be a body that can produce certain effects."
Both conceptions are open to criticism, in my opinion. Ianthe first place, it is not true that the idea of temporal succession exhausts the notion of causality. Scientists may perhaps find it wise to use this conception of cause; indeed, perhaps we ought always to use it in this sense. But it is not true that by a cause we merely mean an invariable antecedent. By a cause we mean not merely a thing or event that has preceded and will precede another; we mean by it a thing or event that is somehow the ground of another, that without which the other could not be, through which or by which the other thing or event is. It is the phenomenon on which the other phenomenon somehow depends and necessarily depends. It cannot be without the other. When two events appear regularly, I feel inclined to regard one as the ground or cause of the other; but this is a thought added to the idea of temporal succession. Temporal coexistence or succession is an invitation to the mind to interpret the phenomena causally, but it is not identical with the causal notion. The essential element in the conception of causes is the idea of ground, the idea that a phenomenon somehow owes its existence to some other phenomenon, that it would not have been and could not have been if the other had not made it possible for it to be. This is because that is, I say. This change has brought about that one. If this one had not been or were not, that one would not be. There is more implied here than the time element. I may say: This change follows that, or accompanies that, exists with that; when this one exists, that one exists. But this is not the same as saying: This one exists because that one exists. Indeed, one may exist simultaneously with the other, and yet the two may not be related as cause and effect. When I say that one thing exists because the other exists, I mean that one cannot be without the other, that the one brought the other one about. When I say: The change a produces the change b, I mean that the change b owes its existence to the change a, that somehow these changes hang together. We have causality when we say one thing is somehow the ground of the other, in the sense that the second owes its existence to the first. Hence the idea of force as something analogous to our will is not essential to the causal conception either. I do not mean to say that the volitional element, as Mill calls it, does not accompany the popular notion of causality; the example of so many thinkers who make it the essential side of causality indicates that it does. Nor do I contend here that we ought not to employ this idea of force or energy in our interpretation of the world; that is a question by itself. What I meant to say is that this volitional element is not the essential element in the causal notion, that the idea of force or will does not give the idea of cause. Before I can have causality, even in cases where I employ the idea of force, I must regard the force as the ground of another phenomenon; I must relate it with that phenomenon. When I apply the causal notion to the relation between mind and body, I do not merely say that the motion of the body follows my feeling of effort, but that it owes its existence to the feeling of effort, that it is through this, brought about by this. In short, the fundamental thought in the notion of causality is the idea of ground. When I have called one thing the ground of another, in the sense mentioned above, I have applied the causal concept. I may then try to picture to myself how one phenomenon brings about the other and introduce into the conception of causality the notion of force, as something analogous to the feeling of effort. Thus, the primitive thinker is supposed to read his own inner experiences into the world; he believes that changes are produced by some power akin to himself in the things or behind them, making them go. This idea of a will is in the course of time modified, stripped of some of its anthropomorphic elements, and reduced to the idea of a force or power, something like the original feeling of effort from which it springs, but with the consciousness left out, as it were.
But we must not forget that this is only a way of interpreting the world, a particular application of causality and not causality itself. I have the idea of causality, when I say this thing is the ground of that, without having a detailed picture of the process by which the second is produced. I may say, for example: An idea is the cause of a feeling. Here I do not necessarily regard the idea as a force or will to which the feeling owes its existence; I may have no notion whatever of how it happens that an idea brings about a feeling; I may simply say: If it were not for the idea, the feeling could not be; the idea is the ground of the feeling. Or I may say a movement is the cause of another movement, my notion being that somehow movement b owes its existence to movement a, that b would not be and could not be if it were not for a.
The truth is that we are not satisfied with the mere statement that one phenomenon is the ground of the other, that is, with applying the notion of causality; but we attempt to make the relation plainer to ourselves, to see how this thing owes its existence to the other, to insert between the imagined ground and the effect other elements. I may imagine, for example, that because a movement in my body was caused by a feeling of effort, all movements are caused that way or similarly. Or I may believe that, because movements are produced by me by laying hold of things, all movements must be produced that way. Now it may perhaps be found necessary to accept one or the other of these modes of interpreting nature; but that is another question. It may be impossible to explain the world without assuming force or without accepting the view that things must touch each other in order to influence each other. That is a problem by itself. I have applied the causal notion when I say that one thing is the ground of the other. I may not have given the true ground; but that is the fault of my science or my metaphysics, and not of my conception of causality. We must not read more into our notion of causality than it contains.
In short, the idea of cause is a very general formula meaning that one phenomenon somehow owes its existence to another, that it would not be if it were not for the other, that the two are not merely coexistent or successive, but that the one is because the other is, that the first has brought the second into existence, that the latter would not have appeared if it had not been for the former. The relation is not a mere temporal and accidental juxtaposition; there is connection here, system, order. Things are conceived as somehow hanging together, as requiring each other, as necessary members of a series. Each one has its place in a system be that system large or small depends on something else; nothing is independent, 'loose and separate’ unrelated; everything has a meaning. This is all that is implied in the idea of causality as such. We do not, however, always stop here in our thinking, but often try to explain how a causes b. That is, we fill in the somewhat empty formula of causality. And here, of course, there are many different conceptions possible, among them that of force, which has its origin in the feeling of effort.
We must also guard against deducing certain consequences from the notion of causality which do not really follow from it but are deduced from other principles which we read into the idea of causality. We apply the causal principle to particular phenomena; we ask, why are they, to what do they owe their existence? Wherever we notice a change, for example, we inquire into the ground of the change and expect to find a ground. We are so sure that there is a ground that we formulate the general law: Everything that happens must have a ground why it happens. This does not mean, however, that every effect must have the same cause. That does not follow from the law as such. It is immaterial to the law as law whether a certain change has the same cause or not. Nor does it follow that things happen in the future exactly as they happened in the past. The belief in the uniformity of nature, in the universal reign of law, is a later product than the belief in causality. Savages do not believe that things happening around them are uncaused; when they are interested enough in their surroundings to observe changes, they certainly suppose that these are caused by something. When they assume the existence of occult powers producing good and evil, they are applying the causal notion. They do not believe in miracles in the sense of events that have no cause; their miracles are always caused by some power. Hence it is not correct to say that, because certain peoples believe in miracles, they have no notion whatever of cause. But primitive peoples, children, uneducated persons, yes, many educated persons, do not form the notion of law, uniformity; they do not necessarily hold that things will always happen which have happened and as they have happened. Belief in the uniformity of nature, as commonly understood, and belief in causality are not the same.
Nor does it follow from the notion of causality that the effect must be identical with the cause, be of the same nature as the cause. The law itself says nothing of the nature of the cause or effect, but simply that nothing can happen without a cause of some kind. It may be true that an effect cannot be produced by anything different from it, but it does not follow from the notion of causality. Of course, if we put into the conception ideas that do not really belong to it, we can spin out of it whatever we choose. If we define causality as will-action, for example, we can say that there is no causality except where there is will, and then read will or something analogous to will into everything. And if we put everything into causality that Riehl, for example, sees in it, we shall have no trouble, perhaps, in obtaining his results. According to him "causality is the application of the principle of ground (der Satz vom Grunde) to the temporal change of phenomena, or in brief: the principle of ground intime." Now, he goes on to say, the sole principle of logical ground is the principle of identity. That is, we demand in logic that every proposition be connected with others, that it be shown to be either a consequence or presupposition of other propositions. Ultimately, we base ourselves upon the principle of identity; our conclusion really follows necessarily from the premises according to the law of identity. In the same way the causal principle is based upon the principle of identity applied in time or to phenomena. Hence the grounding concept (der begrundende Begriff) and the grounded concept (der begrundete) must be similar, homogeneous. For example, we cannot understand psychical effects from physical causes. Moreover, the ground must be sufficient, and the sufficient ground can contain neither more nor less than is necessary for the ground.
Riehl bases the principle of causality upon the principle of identity and applies this to phenomena in time. Whatever is, remains what it is. This means, whatever is, continues to be, persists, lasts, endures. It means that a thing cannot perish, go into nothing; for if it did, it would not persist. Nor can a thing come from nothing. Nothing must remain what it is; if it becomes something, it does not remain nothing. For the same reason the effect must be identical with the cause; the cause must remain what it is or identical with itself.
But Riehl misinterprets the principle of identity, in my opinion. The principle of identity simply declares that whatever is, is, not that a thing must persist or endure in its essence. It holds that when once we have said a thing, we must adhere to it during our argument, that we must remain consistent with ourselves. I cannot say, A thing is, and a thing is not; that is, negate what I have already predicated of a thing. But there is nothing impossible in the statement that a thing is and now is not, that it was and is not. It is not logically necessary that a thing remain what it is, that it does not change. In one case, is merely the sign of logical predication; I say this thing is thus or so, which means this thing has this or that attribute. But when I say this thing is, in the other sense, I mean is in time. So, too, by logical ground we mean to give the reason for a proposition. Isai this man is mortal because all men are mortal. That is, when I say all men are mortal, I cannot say this man is not mortal, for I have already implied that he is, and I must adhere to what I have started out with. If all men are mortal and this one’s a man, then he must be mortal; for whatever is, is. Theological ground, that is, contains the proposition grounded upon it; the latter is really identical with the former. This is what Riehl means when he says: The grounding concept and grounded concept are homogeneous. But it does not follow from this that the cause is identical with the effect: logical ground and real ground are not the same.
The attempts which have been made to deduce the law of the conservation of energy from the law of causality are based upon the same misinterpretation of causality. The reasoning may be summarized as follows: The fundamental law of mind is the principle of identity: Whatever is, is, and nothing can both be and be not. From this principle follows the principle of sufficient reason: Nothing can happen without a sufficient reason for it happening as it does. That is, every effect must have its cause, nothing can happen without a ground. Hence nothing in nature can be created out of nothing, for if it could, we should have an effect without a cause. Nor can anything be lost or disappear, for if it could, we should have a cause without an effect. Accordingly, no form of energy can be lost; when it seems to disappear, it simply changes into a different form, which is equal to its original form, equal to it in quality and in quantity. Thesis the law of the conservation of energy, which is here supposed to follow necessarily from the law of causality, which, in turn, is supposed to be a necessary consequence of the principle of identity.
On the basis of these reasonings the theory of parallelism, too, is conceived as necessarily following from the principle of causality. If the effect must be homogeneous with the cause, then mind cannot be the cause of motion, and vice versa. If motion could be transformed into mind, and mind into motion, then energy would be lost and energy would be created, which is impossible. So mental states cannot produce physical states, nor physical states mental states, and parallelism is the necessary implication of causality.
Our conclusions then, so far, are these: Temporal succession and causality are not identical, nor is the idea of force identical with the notion of causality. The essential element in the causal form is the idea of ground. The principle of the uniformity of nature does not follow necessarily from the notion of causality as such. Nor does it follow from the notion of causality that the effect must be identical with the cause. The principle of the conservation of energy does not follow from the principle of causality as a logical necessity, nor does the theory of psychophysical parallelism.
As we said before, the idea of cause is a general formula, meaning that one phenomenon somehow depends on another. This general principle is employed in the different fields of science where causal explanations are at all possible. Each science, however, gives to it the special form which seems to be required by the condition of that science, or, rather, combines it with its working principles. A science that deals with motion or forces or energies as its fundamental concepts will read into the notion of causality motion, force, or energy; for it every cause will be a movement or a force or an energy; its explanations will all be either mechanical or dynamic. To such a science, teleological interpretation of facts, for example, will seem an absolute violation of the causal principle and the utter abandonment of explanation. For a science that identifies causality with mechanism, the world ceases to have a meaning where motions tops; to it vitalism and teleology will be sheer nonsense. We do not wish to plead the cause of vitalism or teleology here; our purpose is simply to point out that each particular science tries to foist its special form of causality upon its neighbors and to interpret their results in the light of its own working concepts. What particular form the causal principle shall take, i.e., what the nature of the particular causes shall be, whether force or motion or a vital principle, or mind, will depend upon our experiences with the world, and is not deducible from the idea of causality as such.
We are now ready to take up our second question: What is the origin of this principle? How does it arise? Does it come from experience or is it an inherent, a priori possession of the reason? According to the rationalists, it is the latter. That every effect must have its cause is, according to Descartes, an innate principle. Wolff tries to deduce it from the principle of contradiction, which is an a priori truth. He reasons that, if the ground of a thing lies in nothing, then nothing is its ground, which is equivalent to saying that nothing as an efficient principle is something, a contradiction in terms. Kant regards the principle that 'everything that happens presupposes something on which it follows according to rule,' as a category or a proreform of the understanding.
Hume holds that the notion of causality is derived from experience. “The knowledge of this relation [the causal]," he says, “is not, in any instance, attained by reasonings a priori; but arises entirely from experience when we find that any particular objects are constantly conjoined with each other." "The mind can never possibly find the effect in the supposed cause by the most accurate scrutiny and examination. For the effect is totally different from the cause, and consequently can never be discovered in it." We say an event is the effect or cause of another because we have experienced them together. But even after we have experienced the operation of cause and effect, we cannot base our conclusions on reason. We know that bread nourishes us, but how it does this we do not know. We do not know the secret powers that produce the effects. A person brought suddenly into the world, having powers of reflection and reason, would perceive objects succeeding each other and nothing else. If he lives long enough to have observed that similar events or objects are constantly conjoined together, he immediately infers the existence of one object from the appearance of the other. The principle which determines him to draw such a conclusion is the principle of custom or habit. After the constant conjunction of two objects, heat, and flame, for instance, or weight and solidity, we are determined by custom alone to expect the one from the appearance of the other. We believe it. "This belief is the necessary result of placing the mind in such circumstances. It is an operation of the soul, when we are so situated, as unavoidable as to feel the passion of love, when we receive benefits, or hatred, when we have met with injuries. All these operations are a species of natural instincts, which no reasoning or process of the thought and understanding is able either to produce or to prevent."
According to Mill also, the notion of causality is derived from experience. Experience teaches us that every fact in nature is invariably preceded by some other fact. "The belief we are entertaining, the universality, throughout nature, of the law of cause and effect, is itself an instance of induction; and by no means one of the earliest which any of us, or which mankind in general, can have made. We arrive at this universal law by generalization, from many laws of inferior generality. We should never have had the notion of causation (in the philosophical meaning of the term) as a condition of all phenomena, unless many cases of causation, or, in other words, many partial uniformities of sequence, had previously become familiar. The more obvious of the particular uniformities suggest, and give evidence of, the general uniformity, and the general uniformity, once established, enables us to prove the remainder of the particular uniformities of which it is made up."
Erhardt explains as follows: The idea of causing and affecting (Wirken und Bewirken) is originally given by experience; if it were not, no reflection upon the changes could suggest to us the notion of a causal nexus existing between them. But our belief in the universality of the causal law is not derived from induction; we are compelled to ascribe to the law a methodological universality.
These answers are discordant, partly because the conceptions of causality which underlie them differ so much, partly because different phases of the law are discussed. We can at once agree with Hume, that we have no a priori knowledge of particular causal relations; indeed, the rationalists did not commit themselves to this view. Hume is right: "Adam, though his rational faculties be supposed, at the very first, entirely perfect, could not have inferred from the fluidity and transparency of water that it would suffocate him; or from the light and warmth of fire that it would consume him." Kant agrees with this. He does not believe that we have an a priori knowledge of particular causal relations, but that we depend on experience for this. We can also agree with both Hume and Kant that knowledge without experience is impossible, that in order to know we must have sensations. " Gedanken ohne Inhalt sind leer." But is there not an element in the causal notion which cannot be explained, which we shall have to accept, without being able to deduce it from our sensations? The answer to this question will depend in a measure upon our conception of causality. If causality means universal temporal succession merely, then we might say this: Experience teaches us that events follow each other; we infer that because a thing has happened several times, it will happen always. Here the law of uniformity is not something observed by us, but an inference, a leap from the known to the unknown. We do not observe that all events are preceded by other events, but only that some are. We believe, however, that what has happened in the past will happen in the future, this belief is something like an instinct, as Hume himself declares. “I shall add for a further confirmation of the foregoing theory," he says, "that, as this operation of the mind, by which we infer like effects from like causes, and vice versa, is so essential to the subsistence of all human creatures, it is not probable, that it could be trusted to the fallacious deductions of our reason, which is slow in its operation; appears not, in any degree, during the first years of infancy; and at best is, in every age and period of human life, extremely liable to error and mistake. It Is more conformable to the ordinary wisdom of nature to secures necessary an act of the mind, by some instinct or mechanical tendency, which may be infallible in its operations, may discover itself at the first appearance of life and thought, and may be independent of all the labored deductions of the understanding. As nature has taught us the use of our limbs, without giving us the knowledge of the muscles and nerves by which they are actuated; so she has implanted in us an instinct, which carries forward the thought in a correspondent course to that which she has established among external objects; though we are ignorant of those forces and powers on which this regular course and succession of objects totally depends." We have here, then, what may fairly be called an ultimate category. In this sense we can say, even on the empirical interpretation of causality, that there is an element in our conception of because which must be attributed to the nature of man as such.
We may also approach the problem from another side and reason thus: Mere association of ideas would never give us an idea of uniformity; indeed, it would not enable us to connect any two experiences. The halving of a series of sensations or ideas will not yield knowledge; a succession of sensations is not a knowledge of succession. In order to have a consciousness of succession, an additional psychical element must be introduced: a feeling of succession. If our consciousness consisted simply of a series of disconnected mental facts, a heap (ein Haufe, ein Gewuhl) of sensations, as Kant terms it, knowledge would be impossible. As James says: "Take a hundred of them [feelings],shuffle them and pack them as close together as you can(whatever that may mean); still each remains the same feeling it always was, shut in its own skin, windowless, ignorant of what the other feelings are and mean. There would be a hundred and first feeling there, if, when a group or series of such feelings were set up, a consciousness belonging to the group as such should emerge. And this list feeling would be a totally new fact."
Hence, we could not even say, some events succeed each other, if we accepted a purely sensationalistic theory. In order to have this experience, we must, roughly speaking, be able to keep two ideas together in consciousness, we must connect our sensations. The sensations will not connect themselves; we must connect them. This synthetic function we cannot further explain; we are compelled to accept it as a fact of consciousness. We believe that it belongs to the furniture of the mind and in this sense can call it a priori.
Now let us consider our own interpretation of the causal law. We mean by causality the reference of a thing to something else as its ground, as that to which the thing somehow owes its appearance. Here we not only hold two ideas together in consciousness, synthesize them in the manner already indicated, but we view one thing as standing in a particular relation to the other. Whenever we observe an event, we ask for its ground, we ask for some other fact or phenomenon on which it depends. We cannot explain why we do this, it is a way we have, a mental attitude or, if we choose to call it so, an a priori form of the mind. We are so constituted, in other words, that whenever a phenomenon is presented to us, we refer it to another phenomenon as its ground.
It is possible that this function is a product of natural selection, that only such animals as possessed survived in the struggle for existence and handed it down to offspring, and that in this way a race of beings was finally produced having the so-called ‘causal instinct.' But all that does not explain to us the possession of this function by the first animal that handed it down.
We repeat then: The causal function, as we have described it, is a postulate of our thinking, a tendency to connect phenomena in a certain way. It is an attitude of consciousness towards phenomena, a way we have of connecting things, a way that cannot be further explained.
This does not mean that we have an a priori knowledge of the principle as a law, that we know from the very beginning that every phenomenon has its cause. We ask for the cause every time a phenomenon is presented to us, in this sense, the causal idea is a form of the mind, but we do not formulate the general proposition that every effect must have its cause until we reflect upon our experiences, and, in this sense, the causal law is a generalization from experience, the result of induction. There Isa difference between looking for a ground in each particular case presented and formulating the general proposition that every phenomenon must have a ground.
The third question which we have to answer concerns the validity of the causal principle. We relate phenomena according to the notion of cause and effect. We cannot help doing this; it seems to be an inevitable tendency of the mind to connect our facts in the causal manner. We say: This fact or phenomenon is, because that one is or was the two are not only coexistent or successive, but one is the ground of the other, without it the other would not and could not be. Now we may ask two questions here: (I) What right do we have us to regard one phenomenon as the cause of the other? (2) What right have we to say that all phenomena are causally related?
What right have I to speak of a particular phenomenon having ground? I find a phenomenon surrounded by countless other phenomena. I select one of these as the cause of the other. All I perceive is the phenomena themselves. I rub an object and it becomes warm. I say the rubbing made it warm. I heat my body and it expands. I say the heat did it. I see a moving bell; I hear a sound. I say the bell makes the sound. I have a feeling of effort and then my muscles move. I say the feeling of effort or my will causes the movement of my muscles. I remember a certain scene and a sorrowful feeling arises. I say the image is the ground of the sorrowful feeling. Now in all these cases I do not merely say that the different phenomena follow each other, but that the one is the ground of the other. Why should I look for a ground at all, why am I not satisfied with saying, the bell and the sound go together, the sound never comes alone?
Someone perhaps answers: The primitive man learned by experience that he produced changes in the world. He pushed an object and it moved. He therefore regarded himself as the ground of the movement. He did it. Then he reasoned that when other things moved there was something behind them that moved them as he moved them. But the question is: Why should he regard himself as the mover in the first place? You say he perceived himself moving it. No, he did not. He said move, and it moved. All he experienced was that a movement followed his volition. But he does not stop here; he is not satisfied with saying that a movement follows his act of will. He says he made it move, he was the ground of its moving. What right has he to say that? He has a right to say: I pushed, and it moved; I put forth effort and something happened. Perhaps the first time it happened; he did not look upon himself as the ground. He stopped pushing and it stopped moving, he pushed little, and it moved a little, he pushed much, and it moved much. Then he said, I did it, I made it move, I can do it again, I am the cause. Here he reasons that he did it because, when he stops, it stops, when he pushes, it moves. If he should say to the sun, stop shining, and it should stop shining, and, now shine again, and it should shine, he would come to regard himself as the cause of the sunshine.
Here we reach an element which we cannot explain. It is a mental attitude, a postulate of thought, if we choose to call it so we can state the conditions under which it appears, but we cannot tell why it follows these conditions. In order that this causal function shall arise, certain conditions must be fulfilled, but when it arises something new and unique appears on the scene. What justification is there for its use? What are its rights? Well, it is a postulate of our thinking, and there can be no human knowledge without it. The human mind is a relating activity, it aims to understand the world, to find a meaning in it, to bring order and connection into it, to explain it. Wherever a phenomenon is presented, we look for a ground or cause, for dependence, we seek to bring it into connection with something else, we are never satisfied with a bare fact as such. The mere statement of spatial and temporal coexistence or sequence is not an explanation, and without explanation scientific knowledge is impossible. Nor is mere description science, if we mean by description the mere statement of what happens in space and time. If thinking means to relate things in the manner indicated, then we have a right to say that for thought all phenomena are causally related and will be so related as long as thinking is what it is. Where explanation stops, science and philosophy find their occupation gone.