A. The Denial of Final Causes.
The doctrine of final causes in nature must stand or fall with the doctrine of a personal God. The one cannot be denied without denying the other. And the admission of the one involves the admission of the other. By final cause is not meant a mere tendency, or the end to which events either actually or apparently tend; but the end contemplated in the use of means adapted to attain it. The contemplation of an end, is a mental act. The selection and use of means adapted to attain such end, are both intelligent and voluntary acts. But an intelligent voluntary agent is a person.1 In other words, the use of means to accomplish a contemplated end is a function of personality, or at least of intelligent agency.
Such being the nature of final causes, they are of course denied, (1.) By the positivist, who believes nothing but facts of which the senses take cognizance; and who admits of no other causation than regularity of sequence. As efficiency, intention, and mind are not perceived by the senses, they are not, and cannot be philosophically admitted. (2.) By those who, while they admit such a thing as force, and, therefore, in that sense, a cause, allow of no distinction between physical, vital, and mental causes, or forces; and who maintain that the one can be resolved into either of the others. The advocates of this theory make thought a product of the brain; and have as their watch-word, “Ohne Phosphor kein Gedanke.” Of course phosphorus must be before thought, and therefore there can be no final cause in the production of phosphorus, or of anything else. (3.) Final causes are denied by those who regard the universe as the development of the infinite Being under the operation of necessary law. Of that Being no intelligence, consciousness, or will can be predicated. Consequently there can be no preconceived design to be accomplished, either by the universe as a whole, or any of its parts. According to Spinoza, therefore, final causes are “humana figmenta et deliria.”
If you should ask a peasant, where a tree or the body of an animal came from, he would probably answer, “Why, it grew.” That for him is the final fact. And so it is for all the advocates of the above-named theories. Thus it is that extremes (the peasant’s thought and the savant’s theory) meet. What more, what deeper thought is found in the words of Stuart Mill than in the peasant’s answer, when the logician says: “Sequences entirely physical and material, as soon as they had become sufficiently familiar to the human mind, came to be thought perfectly natural, and were regarded not only as needing no explanation themselves, but as being capable of affording it to others, and even of serving as the ultimate explanation of things in general.”2
B. Objections of Hume and Kant.
Hume’s answer to the argument from design, or final causes, is, that our knowledge is limited by experience. We have often seen houses, ships, engines, and other machines made, and therefore, when we see similar products of human skill we are authorized to infer that they too were constructed by an intelligent author. But the world belongs to an entirely different category; we have never seen a world made; and therefore we have no rational ground for assuming that this world had a maker. “When two species of objects,” says Hume,3 “have always been observed to be conjoined together, I can infer, by custom, the existence of one whenever I see the existence of the other, and this I call an argument from experience. But how this argument can have place, where the objects, as in the present case, are single, individual, without parallel, or specific resemblance, may be difficult to explain. And will any man tell me with a serious countenance, that an orderly universe must arise from some thought and art, like the human, because we have experience of it? To ascertain this reasoning, it were requisite that we had experience of the origin of worlds; and it is not sufficient surely that we have seen ships and cities arise from human art and contrivance.” What experience teaches is that design implies intelligence; i.e., that we never see the adaptation of means to an end without having evidence that such adaptation is the work of an intelligent agent. And, therefore, even under the guidance of experience we infer that wherever we see design, whether in nature or in art, there must be an intelligent agent. But experience is not the ground or limit of this conviction. It is an intuitive truth, self-evident from its nature, that design cannot be accounted for on the ground of chance or necessity. Let any man try to persuade himself that a watch is the product of chance, and he will see how futile is the attempt.