all things, are now to be explained as Forms or Types of some things only, — that is to say, of natural objects : these we conceive imperfectly, but are always seeking in vain to have a more perfect notion of them. He says (J. of Philol. xi. 319) that ' Plato hoped by the study of a series of hypothetical or provisional classifications to arrive at one in which nature's distribution of kinds is approximately represented, and so to attain approximately to the knowledge of the ideas. But whereas in the Republic, and even in the Phaedo, though less hopefully, he had sought to convert his provisional definitions into final ones by tracing their connexion with the summxtm genus, the ayaQov, in the Parmenides his aspirations are less ambitious,' and so on. But where does Dr. Jackson find any such notion as this in Plato or anywhere in ancient philosophy? Is it not an anachronism, gracious to the modern physical philosopher, and the more acceptable because it seems to form a link between ancient and modern philosophy, and between physical and metaphysical science ; but really unmeaning ?

(5). To this ' Later Theory' of Plato's Ideas I oppose the authority of Professor Zeller, who affirms that none of the passages to which Dr. Jackson appeals (Theaet. 185 C foil.; Phil. 25 B foil. ; Tim. 57 C ; Parm. 130 B foil, 142 B-155 E, 157 6-159 ^) ' i^"* '^6 smallest degree prove his point '; and that in the second class of dialogues, in which the ' Later Theory of Ideas ' is supposed to be found, quite as clearly as in the first, are admitted Ideas, not only of natural objects, but of properties, relations, works of art, negative notions (Theaet. 176 E ; Parm. 130 B foil. ; Soph. 254 B foil., 258 B) ; and that what Dr. Jackson distinguishes as the first class of dialogues from the second equally assert or imply that the relation of things to the Ideas, is one of