Have we not the right, after the foregoing a.n.a.lysis, to interpret the uniform sequence of events solely as the _necessary_ presupposition of the causal relation? Is it not at the same time the _adequate_ presupposition? Yes, is it not the causal relation itself? As we know, empiricism since Hume has answered the last question in the affirmative, and rationalism since Kant has answered it in the negative.
We, too, have seemingly followed in our discussion the course of empiricism. At least, I find nothing in that discussion which a consistent empiricist might not be willing to concede; that is, if he is ready to set aside the psychological investigation of the actual processes which we here presuppose and make room for a critical a.n.a.lysis of the content of the relation of cause and effect.[11] However, the decision of the question, whether or not empiricism can determine exhaustively the content that we think in the causal relation, depends upon other considerations than those which we have until now been called upon to undertake. We have so far only made clear what every critical a.n.a.lysis of the causal relation has to concede to empiricism. In reality the empiristic hypothesis is inadequate. To be sure, the proof of this inadequacy is not to be taken from the obvious argument which Reid raised against the empiricism of Hume, and which compelled Stuart Mill in his criticism of that attack[12] to abandon his empiristic position at this point. No doubt the conclusion to which we also have come for the time being, goes much too far, the conclusion that the cause is nothing but the uniform _antecedens_ and the effect merely the uniform _consequens_. Were it true, as we have hitherto a.s.sumed, that every uniformly preceding event is to be regarded as cause and every uniformly following event as effect, then day must be looked upon as cause of night and night as cause of day.
[Footnote 11: The difference between the two points of view can be made clearer by an ill.u.s.tration. The case that we shall a.n.a.lyze is the dread of coming into contact with fire.
The psychological a.n.a.lysis of this case has to make clear the mental content of the dread and its causes. Such dread becomes possible only when we are aware of the burning that results from contact with fire. We could have learned to be aware of this either immediately through our own experience, or mediately through the communication of others"
experience. In both cases it is a matter of one or repeated experiences. In all cases the effects of earlier experiences equal a.s.sociation and recall, which, in turn, result in recognition. The recognition explaining the case under discussion arises thus. The present stimuli of visual perception arouse the retained impressions of previous visual perceptions of fire and give rise to the present perception (apperception) by fusing with them. By a process of interweaving, a.s.sociations are joined to this perception.
The apperceptively revived elements which lie at the basis of the content of the perception are interwoven by a.s.sociation with memory elements that retain the additional contents of previous perceptions of fire, viz., the burning, or, again, are interwoven with the memory elements of the communications regarding such burning. By means of this interweaving, the stimulation of the apperceptive element transmits itself to the remaining elements of the a.s.sociation complex. The character of the a.s.sociation is different under different conditions. If it be founded only upon one experience, then there can arise a memory or a recall, in the wider sense, of the foregoing content of the perception and feeling at the time of the burning, or, again, there can arise a revival wherein the stimulated elements of retention remain unconscious. Again, the words of the mother tongue that denote the previous mental content, and which likewise belong to the a.s.sociation complex (the apperceiving ma.s.s, in the wider sense), can be excited in one of these three forms and in addition as abstract verbal ideas. Each one of these forms of verbal discharge can lead to the innervations of the muscles involved in speech, which bring about some sort of oral expression of judgment. Each of these verbal reproductions can be connected with each of the foregoing sensory (_sachlichen_) revivals. Secondly, if the a.s.sociation be founded upon repeated perceptions on the part of the person himself, then all the afore-mentioned possibilities of reproduction become more complicated, and, in addition, the mental revivals contain, more or less, only the common elements of the previous perceptions, _i. e._, reappear in the form of abstract ideas or their corresponding unconscious modifications. In the third case the a.s.sociation is founded upon a communication of others" experience. For the sake of simplicity, let this case be confined to the following instance. The communication consisted in the a.s.sertion: "All fire will burn upon contact." Moreover, this judgment was expressed upon occasion of imminent danger of burning. There can then arise, as is perhaps evident, all the possibilities mentioned in the second case, only that here there will be a stronger tendency toward verbal reproduction and the sensory reproduction will be less fixed.
In the first two cases there was connected with the perception of the burning an intense feeling of pain. In the third the idea of such pain added itself to the visual perception of the moment. The a.s.sociated elements of the earlier mental contents belong likewise to the apperceiving ma.s.s excited at the moment, in fact to that part of it excited by means of a.s.sociation processes, or, as we can again say, depending upon the point from which we take our view, the a.s.sociative or apperceptive completion of the content of present perception. If these pain elements are revived as memories, _i. e._, as elements in consciousness, they give rise to a new disagreeable feeling, which is referred to the possible coming sensation of burning. If the mental modifications corresponding to these pain elements remain unconscious, as is often possible, there arises none the less the same result as regards our feeling, only with less intensity. This feeling tone we call the dread.
As a result of the sum total of the revivals actual and possible, there is finally produced, according to the particular circ.u.mstances, either a motor reaction or an inhibitant of such reaction. Both innervations can take place involuntarily or voluntarily.
The critical a.n.a.lysis of the fact that we dread contact with fire, even has another purpose and accordingly proceeds on other lines. It must make clear under what presuppositions the foresight that lies at the basis of such dread is valid for future experience. It must then formulate the actual process of revival that const.i.tutes the foundation of this feeling as a series of judgments, from which the meaning and interconnection of the several judgments will become clear.
Thus the critical a.n.a.lysis must give a logical presentation of the apperceptive and a.s.sociative processes of revival.
For this purpose the three cases of the psychological a.n.a.lysis reduce themselves to two: viz., first, to the case in which an immediate experience forms the basis, and secondly, to that in which a variety of similar mediately or immediately communicated experiences form such basis.
In the first of these logically differentiated cases, the transformation into the speech of formulated thought leads to the following inference from a.n.a.logy:
Fire A burned.
Fire B is similar to fire A.
---------------------------- Fire B will burn.
In the second case there arises a syllogism of some such form as:
All fire causes burning upon contact.
This present phenomenon is fire.
-------------------------------------------------------- This present phenomenon will cause burning upon contact.
Both premises of this syllogism are inductive inferences, whose implicit meaning becomes clear when we formulate as follows:
All heretofore investigated instances of fire have burned, therefore all fire burns.
The present phenomenon manifests some properties of fire, will consequently have all the properties thereof.
--------------------------------------------------------- The present phenomenon will, in case of contact, cause burning.
The first syllogism goes from the particular to the particular. The second proves itself to be (contrary to the a.n.a.lysis of Stuart Mill) an inference that leads from the general to the particular. For the conclusion is the particular of the second parts of the major and minor premises; and these second parts of the premises are inferred from their first parts in the two possible ways of inductive inference. The latter do not contain the case referred to in the conclusion, but set forth the conditions of carrying a result of previous experience over to a new case with inductive probability, in other words, the conditions of making past experience a means of foreseeing future experience. It would be superfluous to give here the symbols of the two forms of inductive inference.
We remain within the bounds of logical a.n.a.lysis, if we state under what conditions conclusions follow necessarily from their premises, viz., the conclusions of arguments from a.n.a.logy and of syllogisms in the narrower sense, as well as those of the foregoing inductive arguments. For the inference from a.n.a.logy and the two forms of inductive inference, these conditions are the presuppositions already set forth in the text of the present paper, that in the as yet un.o.bserved portion of reality the like causes will be found and they will give rise to like effects. For the syllogism they are the thought that the predicate of a predicate is the (mediate) predicate of the subject. Only the further a.n.a.lysis of these presuppositions, which is undertaken in the text, leads to critical considerations in the narrower sense.]
[Footnote 12: _A System of Logic, Ratiocinative and Inductive_, bk. III, ch. v, -- 6.]
Empiricism can, however, meet this objection without giving up its position; in fact, it can employ the objection as an argument in its favor; for this objection affects only the manifestly imperfect formulation of the doctrine, not the essential arguments.
It should have been pointed out again and again in the foregoing exposition that only in the first indiscriminating view of things may we regard the events given us in perception as the basis of our concepts of cause and effect. All these events are intricately mixed, those that are given in self perception as well as those given in sense perception. The events of both groups flow along continuously. Consequently, as regards time, they permit a division into parts, which division proceeds, not indeed for our perception, but for our scientific thought, in short, conceptually, into infinity. The events of sense perception permit also conceptually of infinite division in their spatial relations.
It is sufficient for our present purpose, if we turn our attention to the question of divisibility in time. This fact of divisibility shows that the events of our perception, which alone we have until now brought under consideration, must be regarded as systems of events. We are therefore called upon to apportion the causal relations among the members of these systems. Only for the indiscriminating view of our practical _Weltanschauung_ is the perceived event _a_ the cause of the perceived event _b_. The more exact a.n.a.lysis of our theoretical apprehension of the world compels us to dissect the events _a_ and _b_ into the parts _a_a , _a_, _a_?--_b_a, _b_, _b_?, and, where occasion calls for it, to continue the same process in turn for these and further components. We have accordingly to relate those parts to one another as causes and effects which, from the present standpoint of a.n.a.lysis, follow one another uniformly and _immediately_, viz., follow one another so that from this standpoint no other intervening event must be presupposed. In this way we come to have a _well-ordered experience_.
The dispositions to such experience which reveal themselves within the field of practical thought taught man long before the beginning of scientific methods not to connect causally day and night with one another, but the rising and setting of the sun with day and night. The theoretical a.n.a.lysis, indeed, goes farther. It teaches that in what is here summed up as rising of the sun and yonder as day, there lie again intricate elements requiring special attention, in our own day extending perhaps to the lines of thought contained in the electro-dynamic theory of light and of electrons. Still the ways of thought remain the same, on all the levels of penetrating a.n.a.lysis. We have throughout to relate to one another as cause and effect those events which, in a well-ordered experience, must be regarded as following one another immediately. The cause is then the _immediate_ uniform _antecedens_, the effect the _immediate_ uniform _consequens_. Otherwise stated, the perceived events that we are accustomed, from the standpoint of the practical _Weltanschauung_, to regard as causes and effects, _e. g._, lightning and thunder, from the theoretical apprehension of the world prove to be infinitely involved collections of events, whose elements must be related to one another as causes and effects in as far as they can be regarded as following one another immediately. No exception is formed by expressions of our rough way of viewing and describing which lead us without hesitation to regard as cause one out of the very many causes of an event, and this, too, not necessarily the immediate uniformly preceding event. All this lies rather in the nature of such a hasty view.
The present limitation of uniform sequence to cases of immediate sequence sets aside, then, the objection from which we started, in that it adopts as its own the essential point in question.
Moreover, the way that leads us to this necessary limitation goes farther: it leads to a strengthening of the empiristic position. It brings us to a point where we see that the most advanced a.n.a.lysis of intricate systems of events immediately given to us in perception as real nowhere reveals more than the simple fact of uniform sequence.
Again where we come to regard the intervals between the events that follow one another immediately as very short, there the uniformity of the time relation makes, it would seem, the events for us merely causes and effects; and as often as we have occasion to proceed to the smaller time differences of a higher order, the same process repeats itself; for we dissect the events that make up our point of departure into ever more complex systems of component events, and the coa.r.s.er relations of uniform sequence into ever finer immediate ones. Nowhere, seemingly, do we get beyond the field of events in uniform sequence, which finally have their foundation in the facts of perception from which they are drawn. Thus there follows from this conceptual refinement of the point of departure only the truth that nothing connects the events as causes and effects except the immediate uniformity of sequence.
None the less, we have to think the empiristic doctrine to the bottom, if we desire to determine whether or not the hypothesis which it offers is really sufficient to enable us to deduce the causal relation. For this purpose let us remind ourselves that the question at issue is, whether or not this relation is merely a temporal connection of events that are given to us in perception or that can be derived from the data of perception.
Besides, let us grant that this relation is as thoroughly valid for the content of our experience as empiricism has always, and rationalism nearly always, maintained. We presuppose, therefore, as granted, that every event is to be regarded as cause, and hence, in the opposite time relation, as effect, mental events that are given to us in self perception no less than the physical whose source is our sense perception. In other words, we a.s.sume that the totality of events in our possible experience presents a closed system of causal series, that is, that every member within each of the contemporary series is connected with the subsequent ones, as well as with the subsequent members of all the other series, backward and forward as cause and effect; and therefore, finally, that every member of every series stands in causal relationship with every member of every other series. We do not then, for the present purpose, burden ourselves with the hypothesis which was touched upon above, that this connection is to be thought of as a continuous one, namely, that other members can be inserted _ad infinitum_ between any two members of the series.
We maintain at the same time that there is no justification for separating from one another the concepts, causality and interaction.
This separation is only to be justified through the metaphysical hypothesis that reality consists in a mult.i.tude of independently existing substances inherently subject to change, and that their mutual interconnection is conditioned by a common dependence upon a first infinite cause.[13] Every connection between cause and effect is mutual, if we a.s.sume with Newton that to every action there is an equal opposing reaction.
[Footnote 13: This doctrine began in the theological evolution of the Christian concept of G.o.d. It was first fundamentally formulated by Leibnitz. It is retained in Kant"s doctrine of the _harmonia generaliter stabilita_ and the latter"s consequences for the critical doctrine of the _mundus intelligibilis_. Hence it permeates the metaphysical doctrines of the systems of the nineteenth century in various ways.]
In that we bring the totality of knowable reality, as far as it is a.n.a.lyzable into events, under the causal relation, we may regard the statement that every event requires us to seek among uniformly preceding events for the sufficient causes of its own reality, namely, _the general causal law_, as the principle of all material sciences. For all individual instances of conformity to law which we can discover in the course of experience are from this point of view only special cases of the general universal conformity to law which we have just formulated.
For the empiristic interpretation, the (general) causal law is only the highest genus of the individual cases of empirically synthetic relations of uniform sequence. Starting from these presuppositions, it cannot be other than a generalization from experience, that is, a carrying over of observed relations of uniform, or, as we may now also say, constant sequence to those which have not been or cannot be objects of observation, as well as to those which we expect to appear in the future. Psychologically regarded, it is merely the most general expression of an expectation, conditioned through a.s.sociative reproduction, of uniform sequence. It is, therefore,--to bring Hume"s doctrine to a conclusion that the father of modern empiricism himself did not draw,--a species of temporal contiguity.
The general validity which we ascribe to the causal law is accordingly a merely empirical one. It can never attain apodeictic or even a.s.sertorical validity, but purely that type of problematic validity which we may call "real" in contradistinction to the other type of problematic validity attained in judgments of objective as well as of subjective and hypothetical possibility.[14] No possible progress of experience can win for the empiristically interpreted causal law any other than this real problematic validity; for experience can never become complete _a parte post_, nor has it ever been complete _a parte ante_. The causal law is valid a.s.sertorically only in so far as it sums up, purely in the way of an inventory, the preceding experiences. We call such a.s.sumptions, drawn from well-ordered experience and of inductive origin, "hypotheses," whether they rest upon generalizing inductive inferences in the narrower sense, or upon specializing inferences from a.n.a.logy. They, and at the same time the empiristically interpreted causal law, are not hypotheses in the sense in which Newton rightly rejected all formation of hypotheses,[15] but are such as are necessarily part of all methods in the sciences of facts in so far as the paths of research lead out beyond the content given immediately in perception to objects of only possible experience.
[Footnote 14: Cf. the author"s _Logik_, bd. I, -- 61.]
[Footnote 15: "_Rationem_ vero harum gravitatis proprietatum ex phaenomenis nondum potui deducere, et hypotheses non fingo. _Quicquid enim ex phaenomenis non deducitur, hypothesis vocanda est_; et hypotheses seu metaphysicae, seu physicae, seu qualitatum occultarum, seu mechanicae, in philosophia experimentali loc.u.m non habent. In hac philosophia propositiones deduc.u.n.tur ex phaenomenis, et redduntur generales per _inductionem_." Newton, at the end of his chief work.]
The a.s.sertion of Stuart Mill, in opposition to this conclusion, that the cause must be thought of as the "invariable antecedent" and, correspondingly, the effect is the "invariable consequent,"[16] does all honor to the genius of the thinker; but it agrees by no means with the empiristic presuppositions which serve as the basis for his conclusions.
For, starting from these presuppositions, the "invariable sequence" can only mean one that is uniform and constant according to past experience, and that we henceforth carry over to not yet observed events as far as these prove in conformity with it, and in this way verify the antic.i.p.ation contained in our general a.s.sertion. The same holds of the a.s.sertion through which Mill endeavors to meet the above-mentioned objection of Reid, namely, that the unchanging sequence must at the same time be demonstrably an "unconditional" one. The language in which experience speaks to us knows the term "the unconditioned" as little as the term "the unchangeable," even though this have, as Mill explains, the meaning that the effect "will be, whatever supposition we may make in regard to all other things," or that the sequence will "be subject to no other than negative conditions." For in these determinations there does not lie exclusively, according to Mill, a probable prediction of the future. "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 const.i.tution of things endures, it always _will_ be so." Likewise, Mill, the man of research, not the empiristic logician, a.s.serts that there belongs to the causal law, besides this generality referring to all possible events of uniform sequence, also an "undoubted a.s.surance;" although he could have here referred to a casual remark of Hume.[17] Such an undoubted a.s.surance, "that for every event ... there is a law to be found, if we only know where to find it," evidently does not know of a knowledge referred exclusively to experience.
[Footnote 16: _Logik_, bk. III, ch. v, -- 2.]
[Footnote 17: _Logic_, bk. III, ch. v, -- 6, and end of -- 2.
Hume says in a note to section VI of his _Enquiry Concerning Human Understanding_: "We ought to divide arguments into _demonstrations_, _proofs_, _and probabilities_. By proofs Meaning such arguments from experience as leave no room for doubt or opposition." The note stands in evident contrast to the well-known remarks at the beginning of section IV, pt. I.]
Hence, if the causal law is, as empiricism to be consistent must maintain, only a general hypothesis which is necessarily subject to verification as experience progresses, then it is not impossible that in the course of experience events will appear that are not preceded or followed uniformly by others, and that accordingly cannot be regarded as causes or effects. According to this interpretation of the causal law, such exceptional events, whether in individual or in repeated cases of perception, must be just as possible as those which in the course of preceding experience have proved themselves to be members of series of constant sequence. On the basis of previous experience, we should only have the right to say that such exceptional cases are less probable; and we might from the same ground expect that, if they could be surely determined, they would only have to be regarded as exceptions to the rule and not, possibly, as signs of a misunderstood universal non-uniformity of occurrence. No one wants to maintain an empirical necessity, that is, a statement that so comprehends a present experience or an hypothesis developed on the basis of present experience that its contradictory is rationally impossible. An event preceded by no other immediately and uniformly as cause would, according to traditional usage, arise out of nothing. An event that was followed immediately and constantly by no other would accordingly be an event that remained without effect, and, did it pa.s.s away, it must disappear into nothing.
The old thought, well known in its scholastic formulation, _ex nihilo nihil fit, in nihilum nihil potest reverti_, is only another expression for the causal law as we have interpreted it above. The contradictories to each of the clauses of the thought just formulated, that something can arise out of nothing and pa.s.s into nothing, remain therefore, as a consequence of empiricism, an improbable thought, to be sure, but none the less a thought to which a real possibility must be ascribed.
It was in all probability this that Stuart Mill wished to convey in the much-debated pa.s.sage: "I am convinced that anyone accustomed to abstraction and a.n.a.lysis, who will fairly exert his faculties for the purpose, will, when his imagination has once learnt to entertain the notion, find no difficulty in conceiving that in some one, for instance, of the many firmaments into which sidereal astronomy now divides the universe, events may succeed one another at random without any fixed law; nor can anything in our experience, or in our mental nature, const.i.tute a sufficient, or indeed any, reason for believing that this is nowhere the case." For Mill immediately calls our attention to the following: "Were we to suppose (what it is perfectly possible to imagine) that the present order of the universe were brought to an end, and that a chaos succeeded in which there was no fixed succession of events, and the past gave no a.s.surance of the future; if a human being were miraculously kept alive to witness this change, he surely would soon cease to believe in any uniformity, the uniformity itself no longer existing."[18]
[Footnote 18: _Logic_, bk. III, ch. xxi, -- 1.]
We can throw light from another side upon the thought that lies in this outcome of the empiristic interpretation of the causal law. If we still desire to give the name "effect" to an event that is preceded uniformly by no other, and that we therefore have to regard as arising out of nothing, then we must say that it is the effect of itself, that is, its cause lies in its own reality, in short, that it is _causa sui_.
Therefore the a.s.sumption that a _causa sui_ has just as much real possibility as have the causes of our experience which are followed uniformly by another event, is a necessary consequence of the empiristic view of causation. This much only remains sure, there is nothing contained in our previous experience that in any way a.s.sures us of the validity of this possible theory.
The empiristic doctrine of causation requires, however, still further conclusions. Our scientific, no less than our practical thought has always been accustomed to regard the relation between cause and effect not as a matter of mere sequence, not therefore as a mere formal temporal one. Rather it has always, in both forms of our thought, stood for a _real_ relation, that is, for a relation of _dynamic dependence_ of effect upon cause. Accordingly, the effect _arises out_ of the cause, is _engendered through_ it, or _brought forth by_ it.
The historical development of this dynamic conception of cause is well known. The old anthropopathic interpretation, which interpolates anthropomorphic and yet superhuman intervention between the events that follow one another uniformly, has maintained itself on into the modern metaphysical hypotheses. It remains standing wherever G.o.d is a.s.sumed as the first cause for the interaction between parts of reality. It is made obscure, but not eliminated, when, in other conceptions of the world, impersonal nature, fate, necessity, the absolute ident.i.ty, or an abstraction related to these, appears in the place of G.o.d. On the other hand, it comes out clearly wherever these two tendencies of thought unite themselves in an anthropopathic pantheism. That is, it rests only upon a difference in strength between the governing religious and scientific interests, whether or not the All-One which unfolds itself in the interconnection and content of reality is thought of more as the immanent G.o.d, or more as substance. Finally, we do not change our position, if the absolute, self-active being (in all these theories a first cause is presupposed as _causa sui_) is degraded to a non-intellectual will.
However, the dynamic interpretation of cause has not remained confined to the field of these general speculations, just because it commanded that field so early. There is a second branch, likewise early evolved from the stem of the anthropopathic interpretation, the doctrine that the causal relations of dependence are effected through "forces." These forces adhere to, or dwell in, the ultimate physical elements which are thought of as ma.s.ses. Again, as spiritual forces they belong to the "soul," which in turn is thought of as a substance. In the modern contrast between attractive and repulsive forces, there lies a remnant of the Empedoklean opposition between Love and Hate. In the various old and new hylozoistic tendencies, the concepts of force and its correlate, ma.s.s, are eclectically united. In consistent materialism as well as spiritualism, and in the abstract dynamism of energetics, the one member is robbed of its independence or even rejected in favor of the other.[19]