Nothing else except Genera and Species can be called Second Essences, or said to belong to the Category Essence; for they alone declare what the First Essence is. If you are asked respecting Sokrates, _What_ he _is_? and if you answer by stating the Species or the Genus to which he belongs--that he is a man or an animal--your answer will be appropriate to the question; and it will be more fully understood if you state the Species than if you state the Genus. But if you answer by stating what belongs to any of the other Categories (viz., that he is white, that he is running), your answer will be inappropriate, and foreign to the question; it will not declare _what_ Sokrates _is_.[37] Accordingly, none of these other Categories can be called Essences. All of them rank as predicates both of First and of Second Essence; just as Second Essences rank as predicates of First Essences.[38] [Footnote 37: Ibid. p. 2, b. 29-37. [Greek: ei)ko/tôs de\ meta\ ta\s prô/tas ou)si/as mo/na tô=n a)/llôn ta\ ei)/dê kai\ ta\ ge/nê deu/terai ou)si/ai le/gontai; mo/na ga\r dêloi= tê\n prô/tên ou)si/an tô=n katêgoroume/nôn. to\n ga/r tina a)/nthrôpon e)a\n a)podidô=| tis ti/ e)sti, to\ me\n ei)=dos ê)\ to\ ge/nos a)podidou\s _oi)kei/ôs a)podô/sei_, kai\ gnôrimô/teron poiê/sei a)/nthrôpon ê)\ zô=|on a)podidou/s; tô=n de\ a)/llôn o(/, ti a)\n a)podidô=| tis, _a)llotri/ôs e)/stai a)podedôkô/s_, oi(=on leuko/n ê)\ tre/chei ê)\ o(tiou=n tô=n toiou/tôn a)podidou/s. Ô(/ste ei)ko/tôs tô=n a)/llôn tau=ta mo/na ou)si/ai le/gontai.]] [Footnote 38: Ibid. p. 3, a. 2.] Essence or Substance is not _in_ a Subject; neither First nor Second Essence. The First Essence is neither _in_ a Subject nor _predicated of_ a Subject; the Second Essences are not _in_ the First, but are _predicated of_ the First. Both the Second Essence, and the definition of the word describing it, may be _predicated of_ the First; that is, the predication is synonymous or univocal; whereas, of that which is _in_ a Subject, the name may often be predicated, but never the definition of the name. What is true of the Second Essence, is true also of the Differentia; that it is not _in_ a Subject, but that it may be _predicated_ univocally _of_ a Subject-- not only its name, but also the definition of its name.[39] [Footnote 39: Ibid. p. 3, a. 7, 21, 34. [Greek: koino\n de\ kata\ pa/sês ou)si/as to\ mê\ e)n u(pokeime/nô| ei)=nai--ou)k i)/dion de\ tê=s tou=to ou)si/as, a)lla\ kai\ ê( diaphora\ tô=n mê\ e)n u(pokeime/nô| e)sti/n--u(pa/rchei de\ tai=s ou)si/ais kai\ tai\s diaphorai=s to\ pa/nta sunônu/môs a)p' au)tô=n le/gesthai.]]