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. [Sidenote: Rise of the Sceptics.]