On the other hand, there was in Socrates only the consciousness of the universal still indefinite and vague; in Plato there appeared for the first time the consciousness of the true character of the universal, and so of its distinction from empirical universals; and in Aristotle this enquiry gave important results. The problem of the nature of the concept became, then and afterwards, interwoven with that other problem of the transcendence or immanence of the concepts; but since, notwithstanding many points of contact, the two problems cannot be completely identified, they must not be confounded. Indeed, the problem of the transcendence or immanence of the universals is reducible to the more general problem of the relation between values and facts, the ideal and the real, what ought to be and what is; whereas the other, concerning the nature of the universals, centres upon the distinction between universals that are truly logical, and pseudological universals, and upon the greater or less admissibility of one or the other or of both, and so upon their mode of relation. The point of contact between the two problems lies in this, that where pure and real universals are denied and only arbitrary and nominal universals allowed to subsist, the question of the immanence or transcendence of the universals also disappears. And as to the first problem and the polemic of Aristotle against Plato concerning the ideas, it has appeared to some critics (to Zeller and others) that Aristotle misunderstood his master and invented an error that Plato had never maintained, or attacked merely certain gross expositions of doctrine which were current in some Platonic school. To others again (to Lotze, for instance), it has seemed that Aristotle thought this problem, at bottom, in the same way as Plato, who by placing the ideas in a hyper-Uranian space, in a super-world or a super-heaven, thus came to refuse to them that reality which Aristotle himself refused to them and to consider them as _values,_ not as _beings;_ although Greek linguistic usage prevented Plato from expressing the difference, just as it prevented Aristotle from expressing the same thing, when it led him to describe genera as "second substances" (δεύτεραι οὺσίαι). However, as regards the first interpretation, it certainly seems to us that it is impossible to raise doubts about such a document as the testimony of Aristotle[4] by means of such frequently uncertain documents as the Platonic dialogues. And as regards the second interpretation, it seems to us that it does not so much purge Plato of the vice of transcendence as convict his adversary also of sharing that vice. On this point the opposition of Aristotle to his predecessor does not coincide with that of modern nominalism and empiricism to philosophic idealism, for the former sets in question the truth of the concept itself. Aristotle denied this truth as little as Plato; indeed