ONE:To estimate how much is yet to be learned in mechanical engineering, we have only to apply the same test, and when we contrast the great variance between the designs of machines and the diversity of their operation, even when applied to similar purposes, their imperfection is at once apparent. It must, however, be considered that if the rules of construction were uniform, and the principles of machine operation as well understood as the strength and arrangement of material in permanent structures, still there would remain the difficulty of adaptation to new [15] processes, which are continually being developed.
ONE:As a result of the foregoing criticism, Aristotle distinguishes four different causes or principles by which all things are determined to be what they areMatter, Form, Agent, and Purpose.226 If, for example, we take a saw, the matter is steel; the form, a toothed blade; the agent or cause of its assuming that shape, a smith; the purpose, to divide wood or stone. When we have enumerated these four principles, we have told everything that can be known about a saw. But Aristotle could not keep the last three separate; he gradually extended the definition of form until it absorbed, or became identified with, agent and purpose.227 It was what we should call the idea of function that facilitated the transition. If the very essence or nature of a saw implies use, activity, movement, how can we define it without telling its purpose? The toothed blade is only intelligible as a cutting, dividing instrument. Again, how came the saw into being? What shaped the steel into that particular form? We have said that it was the smith. But surely that is too vague. The smith is a man, and may be able to exercise other trades as well. Suppose him to be a musician, did he make the saw in that capacity? No; and here comes in a distinction which plays an immense part in Aristotles metaphysics, whence it has passed into our every-day speech. He does not make the saw qua musician but qua smith. He can, however, in the exercise of his trade as smith make many other toolsknives, axes, and so forth. Nevertheless, had he only learned to make saws it would be enough. Therefore, he does not make335 the saw qua axe-maker, he makes it qua saw-maker. Nor, again, does he make it with his whole mind and body, but only with just those thoughts and movements required to give the steel that particular shape. Now, what are these thoughts but the idea of a saw present in his mind and passing through his eyes and hands, till it fixes itself on the steel? The immaterial form of a saw creates the real saw which we use. Let us apply the preceding analogies to a natural object; for example, a man. What is the Form, the definition of a man? Not a being possessing a certain outward shape, for then a marble statue would be a man, which it is not; nor yet a certain assemblage of organs, for then a corpse would be a man, which, according to Aristotle, criticising Democritus, it is not; but a living, feeling, and reasoning being, the end of whose existence is to fulfil all the functions involved in this definition. So, also, the creative cause of a man is another man, who directly impresses the human form on the material supplied by the female organism. In the same way, every definite individual aggregate becomes what it is through the agency of another individual representing the same type in its perfect manifestation.228Plotinus follows up his essay on the Virtues by an essay on Dialectic.498 As a method for attaining perfection, he places dialectic above ethics; and, granting that the apprehension of abstract ideas ranks higher than the performance of social duties, he is quite consistent in so doing. Not much, however, can be made of his few remarks on the subject. They seem to be partly meant for a protest against the Stoic idea that logic is an instrument for acquiring truth rather than truth itself, and also against the Stoic use or abuse of the syllogistic method. In modern phraseology, Plotinus seems to view dialectic as the immanent and eternal process of life itself, rather than as a collection of rules for drawing correct inferences from true propositions, or from propositions assumed to be true. We have seen how he regarded existence in the334 highest sense as identical with the self-thinking of the absolute Nous, and how he attempted to evolve the whole series of archetypal Ideas contained therein from the simple fact of self-consciousness. Thus he would naturally identify dialectic with the subjective reproduction of this objective evolution; and here he would always have before his eyes the splendid programme sketched in Platos Republic.499 His preference of intuitive to discursive reasoning has been quoted by Ritter as a symptom of mysticism. But here, as in so many instances, he follows Aristotle, who also held that simple abstraction is a higher operation, and represents a higher order of real existence than complex ratiocination.500
ONE: CHAPTER XAgain, I think that Zeller quite misconceives the relation between Greek philosophy and Greek life when he attributes the intellectual decline of the post-Aristotelian period, in part at least, to the simultaneous ruin of public spirit and political independence. The degeneracy of poetry and art, of eloquence and history, may perhaps be accounted for in this way, but not the relaxation of philosophical activity. On the contrary, the disappearance of political interests was of all conditions the most favourable to speculation, as witness the Ionians, Democritus, and Aristotle. Had the independence and power of the great city-republics been prolonged much further, it is probableas the example of the Sophists and Socrates seems to showthat philosophy would have becomexi still more absorbingly moral and practical than it actually became in the Stoic, Epicurean, and Sceptical schools. And theoretical studies did, in fact, receive a great impulse from the Macedonian conquest, a large fund of intellectual energy being diverted from public affairs to the pursuit of knowledge, only it took the direction of positive science rather than of general speculation.2
