The Foundations of Normal and Abnormal Psychology/Part 1/XVI
The popular mind regards cause as a straining agency which acts in agony of labor on resisting material, finally fashioning it and giving rise to the effect; such a relation is considered as constituting the very essence of activity. This anthropomorphic or animistic view of cause and effect must be rejected by the scientist. The cause does not beget the effect in labor, in strain. To conceive causes as straining agencies is due to the fact that the popular mind has a tendency to mythological creations, to regard natural phenomena as products fashioned by living agencies. The common-sense man in fashioning his material works with his muscles and experiences muscular sensation of strain, of push and pull, hence in regarding the changes in the course of natural processes, he projects into them his subjective muscular experiences. Science, however, has succeeded in freeing itself from all animism, and does not invoke the will and labor of deities and spirits as the causes of physical phenomena, nor does it regard causes themselves as little deities and sprites with will and strain in the production of effects.
Objectively regarded, what nature presents is only sequences of events, or phenomena, and the only relationship observed between cause and effect is simply one of invariable sequence. If of two phenomena one antecedent and the other consequent, the consequent is invariably observed to depend in its variation on the antecedent, such an antecedent is declared to be the cause of the consequent. To give an illustration. If a stone falls from a certain height on a heap of many layers of thin glass, the stone in falling breaks the glass. We declare the stone to be the cause of the breaking of the glass, why? Because we observe the fall of the stone, and on reproducing the same conditions, the same results follow; fall of stone, then breaking of glass. Furthermore, increasing the weight of the stone, more layers of glass are broken, on decreasing the weight of the stone fewer layers are broken, variations in the consequent depend on the variations of the antecedent. We may similarly change the distance from which the stone falls, and the effect will vary once more. On changing the material of the stone the amount of breakage will vary once more. Furthermore, on changing the consistency of the glass layer the effect will again vary. In short, where the phenomena are observed to stand to each other in functional relation of invariable sequence, the antecedent is declared to be the cause of the consequent, such, as in our example, the fall of the stone is regarded as the cause of the breaking of the glass. What is observed is simply an invariable sequence, so much stone momentum, so much glass breakage. No strain or enforcement are ever observed between causes and effects. No strain is observed in the falling stone to produce the effect, nor is it ever detected that the glass resists and is forced into the broken state by the power of the stone.
Strain, resistance, enforcement, power, are all states drawn from experiences of our psychic life. As Mach puts it: "There is but one sort of constancy which embraces all forms of constancy, constancy of connection (or of relation). The majority of the propositions of natural science express such constancies of connection: 'The tadpole is metamorphosed into a frog; chlorate of sodium makes its appearance in the form of cubes. Rays of light are retilinear. Bodies fall with an acceleration of 9.81.' When these constancies are expressed in concepts we call them laws. Force (in the mechanical significance) is likewise merely a constancy of connections. When I say that a body A exerts a force on a body B, I mean that B, on coming into contraposition with A, is immediately affected by a certain acceleration with respect to A. The singular illusion that the substance A is the absolutely constant vehicle of a force which takes effect immediately' on B's being contraposed to A is easily shaken. . . . The phrases, 'No matter without force, no force without matter,' which are all but abortive attempts to remove a self incurred contradiction, become superfluous on our recognizing only constancies of connection."
Similarly Karl Pearson regards the scientific law "as a brief description in mental short hand of as wide a range as possible of the sequences of our sense-impressions" or experiences. "If the stone from my hand break a window, the cause of the broken window might very likely be spoken of as the moving stone. But although this usage is an approach to the scientific usage of the word cause, it yet involves in the popular estimation an idea of enforcement which is not in the latter. That the stone moving with a certain speed must bring about the destruction of the window is, I think, the idea involved in thus speaking of the moving stone as the cause of the breakage. But were our perceptive organs sufficiently powerful, science conceives that we should see before the impact particles of window and particles of stone moving in a certain manner, and after the impact the same particles moving in a very different manner. We might carefully describe these motions, but we should be unable to say why one stage would follow another, just as we can describe how a stone falls to the earth, but not say why it does. Thus scientifically the idea of necessity in the stages of the sequence―stone in motion, broken window―or the idea of enforcement would disappear; we should have a routine of experience. When we speak however of the stage of a sequence in ordinary life as causes, I do not think it is because we are approaching the scientific standpoint, but I fear it arises from our associating, through long usage the idea of force with the stone. . . . Force as cause of motion is exactly on the same footing as a tree god as cause of growth―both are but names to hide our ignorance of the why in the routine of our perceptions. The necessity in a law of nature has not the logical must of a geometrical theorem, nor the categorical must of a human law-giver; it is merely our experience of a routine whose stages have neither logical nor volitional order. In what we have termed secondary causes (successive stages of the sequence) science finds no element of enforcement, solely the routine of experience."
Within certain limits the psychic process, like the physical process, may be regarded as an activity, as a series of phenomena, as a sequence of antecedents and consequents, or as Pearson puts it, as a routine of experience. This activity of course should not be regarded as a metaphysical agency in the sense of a supersensuous soul, but as a successive series of psychic events. From a scientific standpoint the physical process is regarded as a series of successive physical events. Similarly the psychic process may be regarded as a series of successive states consisting of psychic elements, presentative and representative.
Final, and finite as the psychic process is, it has a series of antecedents and consequents. In so far as these can be traced, one can keep within the bounds of the psychic process only. Furthermore, in so far as the series of psychic antecedents and consequents persists we are fully justified in speaking of the whole series as a process, a form of activity, in short as mental activity.
If by activity is understood the sequence of antecedents and consequents, the position taken by some psychologists in declaring the mental stream as inactive is unacceptable. There is activity in the psychic process, if by activity is meant not the popular belief in actual bonds between cause and effect, but mere sequence of antecedents and consequents. The only difference we can find between them is the finality and finiteness as well as lack of invariable or necessary sequence of antecedents and consequents characteristic of the psychic process in contradistinction to the infinite series and invariable, necessary, or causal sequence, presented by the physical process.