History of the Intellectual Development of Europe, Volume I (of 2) / Revised Edition

by John William Draper

Criticism on the Ideal theory.

Some of the illustrations commonly given of Plato's Ideal theory may also be instructively used for showing the manner in which his facts are dealt with by the methods of modern science. Thus Plato would say that there is contained in every acorn the ideal type of an oak, in accordance with which as soon as suitable circumstances occur, the acorn will develop itself into an oak, and into no other tree. In the act of development of such a seed into its final growth there are, therefore, two things demanding attention, the intrinsic character of the seed and the external forces acting upon it. The Platonic doctrine draws such a distinction emphatically; its essential purpose is to assert the absolute existence and independence of that innate type and its imperishability. Though it requires the agency of external circumstances for its complete realization, its being is altogether irrespective of them. There are, therefore, in such a case, two elements concerned—an internal and an external. A like duality is perceived in many other physiological instances, as in the relationship of mind and matter, thought and sensation. It is the aim of the Platonic philosophy to magnify the internal at the expense of the external in the case of man, thereby asserting the absolute supremacy of intellect; this being the particular in which man is distinguished from the brutes and lower organisms, in whom the external relatively predominates. The development of any such organism, be it plant or animal, is therefore nothing but a manifestation of the Divine idea of Platonism. Many instances of natural history offer striking illustrations, as when that which might have been a branch is developed into a flower, the parts thereof showing a disposition to arrange themselves by fives or by threes. The persistency with which this occurs in organisms of the same species, is, in the Platonic interpretation, a proof that, though individuals may perish, the idea is immortal. How else, in this manner, could the like extricate itself from the unlike; the one deliver itself from, and make itself manifest among the many?

Such is an instance of Plato's views; but the very illustration, thus serving to bring them so explicitly before us, may teach us another, and, perhaps, a more correct doctrine. For, considering the duality presented by such cases, the internal and external, the immortal hidden type and the power acting upon it without, the character and the circumstances, may we not pertinently inquire by what authority does Plato diminish the influence of the latter and enhance the value of the former? Why are facts to be burdened with such hypothetical creations, when it is obvious that a much simpler explanation is sufficient? Let us admit, as our best physiological views direct, that the starting-point of every organism, low or high, vegetable or animal, or whatever else, is a simple cell, the manner of development of which depends altogether on the circumstances and influences to which it is exposed; that, so long as those circumstances are the same the resulting form will be the same, and that as soon as those circumstances differ the resulting form differs too. The offspring is like its parent, not because it includes an immortal typical form, but because it is exposed in development to the same conditions as was its parent. Elsewhere I have endeavoured to show that we must acknowledge this absolute dominion of physical agents over organic forms as the fundamental principle in all the sciences of organization; indeed, the main object of my work on Physiology was to enforce this very doctrine. But such a doctrine is altogether inconsistent with the Ideal theory of Platonism. It is no latent imperishable type existing from eternity that is dominating in such developments, but they take place as the issue of a resistless law, variety being possible under variation of environment. Hence we may perhaps excuse ourselves from that suprasensual world in which reside typical forms, universals, ideas of created things, declining this complex machinery of Platonism, and substituting for it a simple notion of law. Nor shall we find, if from this starting-point we direct our thoughts upward, as Plato did from subordinate ideas to the first idea, anything incompatible with the noble conclusion to which he eventually came, anything incompatible with the majesty of God, whose existence and attributes may be asserted with more precision and distinctness from considerations of the operation of immutable law than they can be from the starting-point of fantastic, imaginary, ideal forms.

Rise of the Sceptics.

We have seen how the pre-Socratic philosophy ended in the Sophists; we have now to see how the post-Socratic ended in the Sceptics. Again was repeated the same result exhibited in former times, that the doctrines of the different schools, even those supposed to be matters of absolute demonstration, were not only essentially different, but in contradiction to one another. Again, therefore, the opinion was resumed that the intellect of man possesses no criterion of truth, being neither able to distinguish among the contradictions of the impressions of the senses, nor to judge of the correctness of philosophical deductions, nor even to determine the intrinsic morality of acts. And, if there be no criterion of truth, there can be no certain ground of science, and there remains nothing for us but doubt. Such was the conclusion to which Pyrrho, the founder of the Sceptics, came. He lived about B.C. 300. His philosophical doctrine of the necessity of suspending or refusing our assent from want of a criterion of judgment led by a natural transition to the moral doctrine that virtue and happiness consist in perfect quiescence or freedom from all mental perturbation. This doctrine, it is said, he had learned in India from the Brahmans, whither he had been in the expedition of Alexander. On his return to Europe he taught these views in his school at Elis; but Greek philosophy, in its own order of advancement, was verging on the discovery of these conclusions.

Secondary analysis of ethical philosophy.

The Sceptical school was thus founded on the assertion that man can never ascertain the true among phenomena, and therefore can never know whether things are in accordance or discordance with their appearances, for the same object appears differently to us in different positions and at different times. Doubtless it also appears differently to various individuals. Among such appearances, how shall we select the true one, and, if we make a selection, how shall we be absolutely certain that we are right? Moreover, the properties we impute to things, such as colour, smell, taste, hardness, and the like, are dependent upon our senses; but we very well know that our senses are perpetually yielding to us contradictory indications, and it is in vain that we expect Reason to enable us to distinguish with correctness, or furnish us a criterion of the truth. The Sceptical school thus made use of the weapon which the Sophists had so destructively employed, directing it, however, chiefly against ethics. But let us ascend a step higher. If we rely upon Reason, how do we know that Reason itself is trustworthy? Do we not want some criterion for it? And, even if such a criterion existed, must we not have for it, in its turn, some higher criterion? The Sceptic thus justified his assertion that to man there is no criterion of truth.

The doctrines of Pyrrho.

In accordance with these principles, the Sceptics denied that we can ever attain to a knowledge of existence from a knowledge of phenomena. They carried their doubt to such an extreme as to assert that we can never know the truth of anything that we have asserted, no, not even the truth of this very assertion itself. "We assert nothing," said they; "no, not even that we assert nothing." They declared that the system of induction is at best only a system of probability, for an induction can only be certain when every one and all of No certainty in knowledge. the individual things have been examined and demonstrated to agree with the universal. If one single exception among myriads of examples be discovered, the induction is destroyed. But how shall we be sure, in any one case, that we have examined all the individuals? therefore we must ever doubt. As to the method of definitions, it is clear that it is altogether useless; for, if we are ignorant of a thing, we cannot define it, and if we know a thing, a definition adds nothing to our knowledge. In thus destroying definitions and inductions they destroyed all philosophical method.

The doctrines of Epicurus.