in being, by thought and the mind?' 'Yes.' And you mean by the word 'participation' a power of doing or suffering? To this they answer--I am acquainted with them, Theaetetus, and know their ways better than you do--that being can neither do nor suffer, though becoming may. And we rejoin: Does not the soul know? And is not 'being' known? And are not 'knowing' and 'being known' active and passive? That which is known is affected by knowledge, and therefore is in motion. And, indeed, how can we imagine that perfect being is a mere everlasting form, devoid of motion and soul? for there can be no thought without soul, nor can soul be devoid of motion. But neither can thought or mind be devoid of some principle of rest or stability. And as children say entreatingly, 'Give us both,' so the philosopher must include both the moveable and immoveable in his idea of being. And yet, alas! he and we are in the same difficulty with which we reproached the dualists; for motion and rest are contradictions--how then can they both exist? Does he who affirms this mean to say that motion is rest, or rest motion? 'No; he means to assert the existence of some third thing, different from them both, which neither rests nor moves.' But how can there be anything which neither rests nor moves? Here is a second difficulty about being, quite as great as that about not-being. And we may hope that any light which is thrown upon the one may extend to the other. Leaving them for the present, let us enquire what we mean by giving many names to the same thing, e.g. white, good, tall, to man; out of which tyros old and young derive such a feast of amusement. Their meagre minds refuse to predicate anything of anything; they say that good is good, and man is man; and that to affirm one of the other would be making the many one and the one many. Let us place them in a class with our previous opponents, and interrogate both of them at once. Shall we assume (1) that being and rest and motion, and all other things, are incommunicable with one another? or (2) that they all have indiscriminate communion? or (3) that there is communion of some and not of others? And we will consider the first hypothesis first of all.