the Theaetetus in which Socrates is the principal speaker. The issue propounded is the question whether the "good" is pleasurable feeling or whether it is thought, the exercise of intelligence.
Comparison with the notices of Aristotle in the Nicomachean Ethics shows that this was the subject of a sharp division in the Academy, the Hedonist party being led by the mathematician and astronomer Eudoxus, the anti-Hedonists by Speusippus. Under the guidance of Socrates the question is narrowed down to a con sideration of the good for man in particular, and a mediating con clusion is reached. The best life for man contains both elements, but intelligence is the "predominant partner." All forms of knowledge find a place in it, but only those pleas ures which are compatible with wisdom and virtue, i.e.,those which are "unmixed," not preceded by a sense of want or craving, and those of the "mixed" pleasures, the satisfactions of appetite, which are innocent and moderate. The Philebus contains Plato's ripest moral psychology; it is the immediate source of the famous "doctrine of the Mean." Philosophically the most important feature of the dialogue is a classification adopted with a view to determining the formal char acter of the two claimants to recognition as the good. All corn ponents of the actual belong to one of four classes, (I) the in finite or unbounded (Itretpov), (2) the limit (7rpas), (3) the mix ture or combination of (I) and (2), (4) the cause of the mixture. ( [I] and [2] are just the two fundamental "opposites" of Pythag oreanism.) All the good things of life belong to (3), that is, they are produced by the introduction of definite "limit" or "ratio" into an indeterminate "continuum." (This is precisely the doctrine of the "Mean.") The establishment of such a "ratio" is a *eats Els oboiap, a process resulting in a stable "being," and it is indi cated that the cause or agent in such a process is always intelli gence, human or divine.
There has been much discussion of the question in which of these "classes" the Forms should be placed. The only tenable alternatives would be to put them into the class of "limit" or into that of the "mixture" (a view suggested both by the teaching of the Sophistes and by Aristotle's express statement that Plato dis tinguished two constituents within the Form and advocated ably by Dr. H. Jackson). The truth seems to be that the particular classi fication in the Philebus is devised for a special purpose, and that it is not intended to apply to anything but the things and processes of the sensible realm. In that case, though there is a close cor respondence between what the Philebus teaches about "stable being" in the sensible realm and what, as we know from Aristotle, Plato taught about the Forms, it will be a mistake to look for any actual exposition of the metaphysic of the Forms in the Philebus.
rative of the gallantry of the prehistoric Athenians who defeated the kings of the imaginary Atlantis in their ambitious attempt to become masters of the world. The story was to have been told more in detail in the unfinished Critias.
Timaeus opens his discussion by drawing a sharp distinction be tween eternal being and temporal becoming, and insisting on the point that it is only of the former that we can have exact and final knowledge. All accounts of the temporal can be only tentative and liable to repeated revision. Cosmology, then, at best, is not exact science. The visible world, being mutable and temporal, is a copy of a model which is eternal, and the copy is the work of God. The reason why there is a copy at all is the unceasingly active and generous goodness of God. (In the sequel Timaeus speaks of the Forms which God had before Him as His model in much the same language as the Phaedo, except that he uses the Pythagorean word "imitation," not "participation," to describe the relation of sensible things to Forms.) The world, then, had a beginning. (The Academic tradition from the first was that this is not to be understood literally: Aristotle insists on taking it literally.) God first formed its soul out of three constituents, Identity, Difference, Being. Its body was made later from the four Empedoclean "elements." The world-soul was placed in the circles of the sidereal Equator and Ecliptic, the latter being split into seven lesser circles, those of the planets, and the two were animated with movements in opposite senses. Subsequently were formed the various subordinate gods and the souls of human beings, that is the "immortal" and rational element in the human soul, which come straight from the hands of God Himself. The formation of the human body and of the two lower "mortal" com ponents of the human soul was effected through the intermediacy of the "created gods" (i.e., the stars). The most important ques tion of detail arising from this part of the dialogue is that debated between Boeckh and Grote. Does Timaeus ascribe a motion to the earth? The restoration of the correct text at 400, proves definitely that he does, but it is not a diurnal revolution, as Grote supposed; it must be rectilinear displacement of unknown period. The con tact is made between Pythagorean geometry and the Empedoclean biology which will be needed for the physiology and medicine of the dialogue by a mathematical construction of the "elements." Starting with two primitive triangles, the isosceles right-angled, and the right-angled scalene in which the hypotenuse is double the shortest side, Timaeus constructs four of the regular solids, cube, tetrahedron, octahedron, icosahedron, and these are assumed to be the shapes of the corpuscles of earth, fire, air, water. These four in their turn are the immediate constituents of all organic and inorganic compounds.