Aristotle himself does not announce these six treatises as forming a distinct aggregate, nor as belonging to one and the same department, nor as bearing one comprehensive name. We find indeed in the Topica references to the Analytica, and in the Analytica references to the Topica. In both of them, the ten Categories are assumed and presupposed, though the treatise describing them is not expressly mentioned: to both also, the contents of the treatise De Interpretatione or Enunciatione, though it is not named, are indispensable. The affinity and interdependence of the six is evident, and justifies the practice of the commentators in treating them as belonging to one and the same department. To that department there belonged also several other treatises of Aristotle, not now preserved, but specified in the catalogue of his lost works; and these his disciple Theophrastus, Eudemus, and Phanias, had before them. As all these three disciples composed treatises of their own on the same or similar topics,[5] amplifying, elucidating, or controverting the views of their master, the Peripatetics immediately succeeding them must have possessed a copious logical literature, in which the six treatises now constituting the Organon appeared as portions, but not as a special aggregate in themselves. [Footnote 5: Ammonius ap. Schol. p. 28, a. 41; p. 33, b. 27, Br.] Of the two treatises which stand first in the Aristotelian Organon--the Categoriæ and the De Interpretatione--each forms in a certain sense the complement of the other. The treatise De Interpretatione handles Propositions (combinations of terms in the way of Subject and Predicate), with prominent reference to the specific attribute of a Proposition--the being true or false, the object of belief or disbelief; the treatise Categoriæ deals with these same Terms (to use Aristotle's own phrase) pronounced without or apart from such combination. In his definition of the simple Term, the Proposition is at the same time assumed to be foreknown as the correlate or antithesis to it.[6] [Footnote 6: [Greek: Ta\ a)/neu sumplokê=s lego/mena--tô=n kata\ mêdemi/an sumplokê\n legome/nôna] Categ. p. 1, a. 16, b. 25). See Schol. ad Aristot. Physica, p. 323, b. 25, Br.; and Bonitz ad Aristotel. Metaph. (A. p. 987) p. 90. The Categories of Aristotle appear to formed one of the most prominent topics of the teaching of Themistius: rebutting the charge, advanced both against himself, and, in earlier days, against Sokrates and the Sophists, of rendering his pupils presumptuous and conceited, he asks, [Greek: ê)kou/sate de\ au)= tinos tô=n e)mô=n e)pitêdei/ôn u(psêlogoume/nou kai\ brenthuome/nou _e)pi\ toi=s sunônu/mois ê)\ o(mônu/moi=s ê)\ parônu/mois_]; (Orat. xxiii. p. 351.)