402 PLATO, to thinking, but which require intuition in the case of sensuous objects, from the immediate grasp by thought of intelligible objects or ideas themselves, that is, of ultimate principles, devoid of all pre- supposition [Sidvoia, vovs). To the first gradation of science, that is, of the higher department of thinking, belong principally, though not exclu- sively, mathematics ; and that Plato regarded them (though he did not fully realise this notion) as a necessary means for elevating experience into scientific knowledge, is evident from hints that occur elsewhere. (Comp, Brandis, Hatidbiich, &c. vol. ii. pp. 269, &c.— 274, &c.) The fourfold di- vision which he brings forward, and which is dis- cussed in the De Repuhlica (vi. p. 509, &c.) he appears to have taken up more definitely in his oral lectures, and in the first department to have distinguished perception from experience [oiaQriais from ^6^a in the second to have distinguished mediate knowledge from the immediate thinking consciousness of first principles (eTTKTTTjfirj from vovs • see Arist. De Anima^ i. 2, with the note of Trendelenburg). Although, therefore, the carrying out of Plato's dialectics may be imperfect, and by no means proportional to this excellent foundation, yet he had certainly taken a steady view of their end, namely, to lay hold of ideas more and more distinctly in their organic connection at once with one another and with the phenomenal world, by the discovery of their inward relations ; and then having done this, to refer them to their ultimate basis. This ought at the same time to verify itself as the unconditional ground of the reality of objects and of the power we have to take cognisance of them, of Being and of Thought ; being comparable to the intellectual sun. Now this absolutely unconditional ground Plato de- scribes as the idea of the good (De Rep. vi. p. 505, &c.), convinced that we cannot imagine any higher definitude than the good; but that we must, on the contrary, measure all other definitudes by it, and regard it as the aim and purpose of all our endeavours, nay of all developments. Not being in a condition to grasp the idea of the good with full distinctness, we are able to approximate to it only so far as we elevate the power of thinking to its original purity (Brandis, ibid. pp. 281, &c. 324, &c.). Although the idea of the good, as the ultimate basis both of the mind and of the realities laid hold of by it, of thought and of existence, is, according to him, more elevated than that of spirit or actual exist- ence itself, yet we can only imagine its activity as the activity of the mind. Through its activity the determinate natures of the ideas, which in them- selves only exist, acquire their power of causation, a power which must be set down as spiritual, that is, free. Plato, therefore, describes the idea of the good, or the Godhead, sometimes teleologically, as the ultimate purpose of all conditioned existence ; sometimes cosmologically, as the ultimate operative cause ; and has begun to develope the cosmological, as also the physico-theological proof for the being of God ; but has referred both back to the idea of the Good, as the necessary presupposition to all other ideas, and our cognition of them. Moreover, we find hira earnestly endeavouring to purify and free from its restrictions the idea of the Godhead, to establish and defenji the belief in a wise and divine government of the world ; as also to set PLATO. aside the doubt that arises from the existence of evil and suffering in the world. (Brandis, Ibid. p. 331, &c.) But then, how does the sensuous world, the world of phenomena, come into existence ? To suppose that in his view it was nothing else than the mere subjective appearance which springs from the commingling of the ideas, or the confused con- ception of the ideas (Ritter, Geschichte der Philo- Sophie., vol. ii. pp. 295, &c. 339, &c.), not only contradicts the declarations of Plato in the Philebus (p. 23, b. 54, a.), Timaeus (pp.27, e. 48, e. 51), &c., but contradicts also the dualistic tendency of the whole of the ancient philosophy. He desig- nates as the, we may perhaps say, material ground of the phenomenal world, that which is in itself unlimited, ever in a process of becoming, never really existing, the mass out of which every thing is formed, and connects with it the idea of ex- tension, as also of unregulated motion ; attributes to it only the joint causality of necessity, in opposition to the free causality of ideas, which works towards ends, and, by means of his mythical conception of the soul of the universe, seeks to fill up the chasm between these opposed primary essences. This, standing midway between the intelligible (that to which the attribute of sameness belongs) and the sensible (the diverse), as the principle of order and motion in the world, according to him, com- prehends in itself all the relations of number and measure. Plato had made another attempt to fill up the gap in the development of ideas by a sym- bolical representation, in the lectures he delivered upon the Good, mentioned by Aristotle and others. In these he partly referred ideas to intelligible numbers, in order, probably, that he might be able to denote more definitely their relation of de- pendence on the Godhead, as the absolute one, as also the relation of their succession and mutual connection ; and partly described the Godhead as the ultimate ground both of ideas and also of the material of phenomena, inasmuch as he referred them both to the divine causality — the former immediately as original numbers, the latter through the medium of the activity of the ideas. But on this Pythagorean mode of exhibiting the highest principles of Plato's doctrine we have but very im- perfect information. (Brandis, Ibid, yol.ii. ], p. 336, &c.) Both these departments which form the con- necting link between Dialectics and Physics, and the principles of Physics themselves, contain only preliminary assumptions and hypothetical decla- rations, which Plato describes as a kind of recrea- tion from more earnest search after the really ex- istent, as an innocent enjoyment, a rational sport {Tim. pp. 27, e. 29, b. 59, c). Inasmuch as physics treat only of the changeable and imitative, they must be contented with attaining probability ; but they should aim, especially, at investigating teleologically end-causes, that is, free causality, and showing how they converge in the realisation of the idea of the good. All the determinations of the original undetermined matter are realised by corporeal forms; in these forms Plato attempts to find the natural or necessary basis of the different kinds of feeling and of sensuous perception. Throughout the whole development, however, of his Physiology, as also in the outlines of his doc- trine on Health and Sickness, pregnant ideas and clear views are to be met with. (See especially
