TWO:One thing more must be noticed, a matter of some intricacy, but without which, all that has been explained would fail to give a proper idea of steam-hammer-action. The valve motions are alluded to.The tender is almost thereoh! gasped Sandy, the seaplane must be rammed by the tender!
THREE:And the how and the why.
THREE:"Come out of it, my lad," said the gruff one good-humouredly. "We've got you."
THREE: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.228It has been the fashion in certain quarters to look down on these early thinkersto depreciate the value of their speculations because they were thinkers, because, as we have already noticed, they reached their most important conclusions by thinking, the means of truly scientific observation not being within their reach. Nevertheless, they performed services to humanity comparable for value with the legislation of Solon and Cleisthenes, or the victories of Marathon and Salamis; while their creative imagination was not inferior to that of the great lyric and dramatic poets, the great architects and sculptors, whose contemporaries they were. They first taught men to distinguish between the realities of nature and the illusions of sense; they discovered or divined the indestructibility of matter and its atomic constitution; they taught that space is infinite, a conception so far from being self-evident that it transcended the capacity of Aristotle to grasp; they held that the seemingly eternal universe was brought into its present form by the operation of mechanical forces which will also effect its dissolution; confronted by the seeming permanence and solidity of our planet, with the innumerable varieties of life to be found on its surface, they declared that all things had arisen by differentiation8 from a homogeneous attenuated vapour; while one of them went so far as to surmise that man is descended from an aquatic animal. But higher still than these fragmentary glimpses and anticipations of a theory which still awaits confirmation from experience, we must place their central doctrine, that the universe is a cosmos, an ordered whole governed by number and law, not a blind conflict of semi-conscious agents, or a theatre for the arbitrary interference of partial, jealous,6 and vindictive gods; that its changes are determined, if at all, by an immanent unchanging reason; and that those celestial luminaries which had drawn to themselves in every age the unquestioning worship of all mankind were, in truth, nothing more than fiery masses of inanimate matter. Thus, even if the early Greek thinkers were not scientific, they first made science possible by substituting for a theory of the universe which is its direct negation, one that methodised observation has increasingly tended to confirm. The garland of poetic praise woven by Lucretius for his adored master should have been dedicated to them, and to them alone. His noble enthusiasm was really inspired by their lessons, not by the wearisome trifling of a moralist who knew little and cared less about those studies in which the whole soul of his Roman disciple was absorbed.
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