(f) The efficient cause, like other causes, may be either partial or total, according as it produces the effect by co-operation with other causes, or by itself alone. The aim of the inductive sciences is to discover for each kind of natural event or phenomenon the “total cause” in the comprehensive sense of the whole group of positive agencies or causes proper, and negative antecedent and [pg 379] concomitant conditions which are indispensable and necessitating principles of the happening of such kind of event.[463]
(g) We can distinguish between the immediate or determining, the more or less proximate, and the more or less remote, efficient causes of an event. Thus, the application of the fuse to the charge of dynamite in a rock is the immediate or determining cause of the explosion which bursts the rock; the lighting of the fuse, the placing of the charge, etc., the more proximate causes; the making of the fuse, dynamite, instruments, etc., the more remote causes. Again the aim of the inductive sciences is to discover the “total proximate cause” of events,[464] leaving the investigation of ultimate causes, as well as the analysis of causality itself, to philosophy.
(h) Finally, we must distinguish between the individual agent itself as cause (the suppositum or person that acts); the agent's nature and active power as causes; and the action, or exercise of this power as cause. The former, the individual, concrete agent, is the “principium quod agit,” and is called the “causa ut quae”. The nature and the active power of the agent are each a “principium quo agens agit,” the remote and the proximate principle of action respectively; and each is called a “causa ut qua”. The action of the agent is the cause of the effect in the sense that the actual production or fieri of anything is the immediate cause of this thing in facto esse. Corresponding to these distinctions we distinguish between the cause in actu primo remoto, in actu primo proximo, and in actu secundo. These distinctions are of no little importance. By ignoring them, and by losing sight of the intrinsic (formal and material) causes of natural phenomena, many modern scientists and philosophers have confounded cause and effect with the process itself of causation, and declared that cause and effect are not distinct realities, but only two mental aspects of one and the same reality.[465]
The same may be said of all the distinctions so far enumerated. They are absolutely essential to the formation of clear ideas on the question of causality. No term in familiar use is of more profound philosophical significance, and at the same time more elastic and ambiguous in its popular meanings, than the term cause. This is keenly felt in the Logic of the Inductive Sciences, where not only the discovery, but the exact measurement, of physical causes, is the goal of research.
“When we call one thing,” writes Mr. Joseph,[466] “the cause of another, the real relation between them is not always the same.... We say that [pg 380] molecular action is the cause of heat, that the heat of the sun is the cause of growth, that starvation is sometimes the cause of death, that jealousy is a frequent cause of crime. We should in the first case maintain that cause and effect are reciprocally necessary; no heat without molecular motion and no molecular motion without heat. In the second the effect cannot exist without the cause, but the cause may exist without the effect, for the sun shines on the moon but nothing grows there. In the third the cause cannot exist without the effect, for starvation must produce death, but the effect may exist without the cause, since death need not have been produced by starvation. In the fourth case we can have the cause without the effect, and also the effect without the cause; for jealousy may exist without producing crime, and crime may occur without the motive of jealousy. It is plain then that we do not always mean the same thing by our words when we say that two things are related as cause and effect; and anyone who would classify and name the various modes in which two things may be causally related would do a great service to clear thinking.”
In the popular acceptation of the term cause, the same kind of event can have a plurality of (efficient) causes. Death, for example, may be brought about in different cases by different diseases or accidents. But if we understand by the total efficient cause of any given kind of effect the sum-total of agencies and conditions which when present necessitate this kind of an effect, and which are collectively and severally indispensable for its production, then it is obvious that a given kind of effect can have only one kind of such total group of antecedents as total cause, just as any one individual effect can have only one individual total cause, viz. the one which actually produced it; a similar total cause would produce a similar effect, but could not produce the numerically identical individual effect of the other similar cause.[467]
The medieval scholastics discussed the question in connexion with the problem of individuation: “Would Alexander the Great have been the same individual had he been born of other parents than Philip and Olympia?” The question is hardly intelligible. The person born of these other parents might indeed have been as similar as you will to the actual Alexander of history, but would not and could not have been the actual Alexander of history. Nowadays the question discussed in this connexion is not so much whether the same kind of natural phenomenon can be produced by different kinds of total cause—for the answer to this question depends wholly on the wider or the narrower meaning attached to the term “total cause,”[468]—but rather whether or how far the inductive scientist's ideal of searching always for the necessitating and indispensable cause (or, as it is also called, the “reciprocating” or “commensurate” cause) is a practical ideal.