ONE:Before ascertaining in what direction Plato sought for an outlet from these accumulated difficulties, we have to glance at a Dialogue belonging apparently to his earliest compositions, but in one respect occupying a position apart from the rest. The Crito tells us for what reasons Socrates refused to escape from the fate which awaited him in prison, as, with the assistance of generous friends, he might easily have done. The aged philosopher considered that by adopting such a course he would be setting the Athenian laws at defiance, and doing what in him lay to destroy their validity. Now, we know that the historical Socrates held justice to consist in obedience to the law of the land; and here for once we find Plato agreeing with him on a definite and positive issue. Such a sudden and singular abandonment of the sceptical attitude merits our attention. It might, indeed, be said that Platos inconsistencies defy all attempts at reconciliation, and that in this instance the desire to set his maligned friend in a favourable light triumphed over the claims of an impracticable logic. We think, however, that a deeper and truer solution can be found. If the Crito inculcates obedience to the laws as a binding obligation, it is not for the reasons which, according to Xenophon, were adduced by the real Socrates in his dispute with the Sophist Hippias; general utility and private interest were the sole grounds appealed to then. Plato, on185 the other hand, ignores all such external considerations. True to his usual method, he reduces the legal conscience to a purely dialectical process. Just as in an argument the disputants are, or ought to be, bound by their own admissions, so also the citizen is bound by a tacit compact to fulfil the laws whose protection he has enjoyed and of whose claims his protracted residence is an acknowledgment. Here there is no need of a transcendent foundation for morality, as none but logical considerations come into play. And it also deserves to be noticed that, where this very idea of an obligation based on acceptance of services had been employed by Socrates, it was discarded by Plato. In the Euthyphro, a Dialogue devoted to the discussion of piety, the theory that religion rests on an exchange of good offices between gods and men is mentioned only to be scornfully rejected. Equally remarkable, and equally in advance of the Socratic standpoint, is a principle enunciated in the Crito, that retaliation is wrong, and that evil should never be returned for evil.120 And both are distinct anticipations of the earliest Christian teaching, though both are implicitly contradicted by the so-called religious services celebrated in Christian churches and by the doctrine of a divine retribution which is only not retaliatory because it is infinitely in excess of the provocation received.Plotinus, as we have said, starts with the Aristotelian account of Matter; but by a process of dialectical manipulation, he gradually brings it into almost complete agreement with Platos conception; thus, as usual, mediating between and combining the views of his two great authorities. In the first place, he takes advantage of Aristotles distinction between intelligible and sensible Matter, to strip the latter of that positive and vital significance with which it had been clothed in the Peripatetic system. In the world of Ideas, there is an element common to all specific forms, a fundamental unity in which they meet and inhere, which may without impropriety be called their Matter. But this Matter is an eternal and divine substance, inseparably united with the fixed forms which it supports, and, therefore, something which, equally with them, receives light and life and thought from the central source of being. It is otherwise with sensible Matter, the common substance of the corporeal elements. This is, to use the energetic expression of our philosopher, a decorated corpse.481 It does not remain constantly combined with any form, but is for ever passing from one to another, without manifesting a particular preference for any. As such, it is the absolute negation of Form, and can only be conceived, if at all, by326 thinking away every sensible quality. Neither has it any quantity, for quantity means magnitude, and magnitude implies definite figure. Aristotle opposed to each particular form a corresponding privation, and placed Matter midway between them. Plotinus, on the other hand, identifies Matter with the general privation of all forms. It is at this point that he begins to work his way back to the Platonic notion of Matter as simple extension. There must, after all, be something about Matter which enables it to receive every kind of quality and figure,it must have some sort of mass or bulk, not, indeed, in any definite sense, but with an equal capacity for expansion and for contraction. Now, says Plotinus, the very indeterminateness of Matter is precisely the capacity for extension in all directions that we require. Having no principle of stability, but being borne towards every form, and easily led about in all directions, it acquires the nature of a mass.482
TWO:In constructing patterns where it is optional whether to employ cores or not, and in preparing drawings for castings which may have either a ribbed or a cored section, it is nearly always best to employ cores. The usual estimate of the difference between the cost of moulding rib and cored sections, as well as of skeleton and cored patterns, is wrong. The expense of cores is often balanced by the advantage of having an 'open mould,' that is accessible for repairs or facing, and by the greater durability and convenience of the solid patterns. Taking, for example, a column, or box frame for machinery, that might be made either with a rib or a cored section, it would at first thought seem that patterns for a cored casting would cost much more by reason of the core-boxes; but it must be remembered that in most patterns labour is the principal expense, and what is lost in the extra lumber required for a core-box or in making a solid pattern is in many cases more than represented in the greater amount of labour required to construct a rib pattern.
FORE:VII.
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