When we compare the doctrine of musical ethos as we find it in these later writers with the indications to be gathered from Plato and Aristotle, the chief difference appears to be that we no longer hear of the ethos of particular modes, but only of that of three or (at the most) four portions of the scale. The principle of the division, it is evident, is simply difference of pitch. But if that was the basis of the ethical effect of music in later times, the circumstance goes far to confirm us in the conclusion that it was the pitch of the music, rather than any difference in the succession of the intervals, that principally determined the ethical character of the older modes. § 26. _The Ethos of the Genera and Species._ Although the pitch of a musical composition--as these passages confirm us in believing--was the chief ground of its ethical character, it cannot be said that no other element entered into the case. In the passage quoted above from Aristides Quintilianus (p. 13 Meib.) it is said that ethos depends first on pitch ([Greek: hetera êthê tois oxyterois, hetera tois baryterois]), and secondly on the moveable notes, that is to say, on the _genus_. For that is evidently involved in the words that follow: [Greek: kai hetera men parypatoeidesin, hetera de lichanoeidesin.] By [Greek: parypatoeideis] and [Greek: lichanoeideis] he means all the moveable notes ([Greek: phthongoi pheromenoi]): the first are those which hold the place of Parhypatê in their tetrachord, viz. the notes called Parhypatê or Tritê: the second are similarly the notes called Lichanos or Paranêtê. These moveable notes, then, give an ethos to the music because they determine the genus of the scale. Regarding the particular ethos belonging to the different genera, there is a statement of the same author (p. 111) to the effect that the Diatonic is masculine and austere ([Greek: arrhenôpon d' esti kai austêroteron]), the Chromatic sweet and plaintive ([Greek: hêdiston te kai goeron]), the Enharmonic stirring and pleasing ([Greek: diegertikon d' esti touto kai êpion]). The criticism doubtless came from some earlier source. Do we ever find ethos attributed to this or that _species_ of the Octave? I can find no passage in which this source of ethos is indicated. Even Ptolemy, who is the chief authority (as we shall see) for the value of the species, and who makes least of mere difference of pitch, recognises only two forms of modulation in the course of a melody, viz. change of genus and change of pitch[1]. § 27. _The Musical Notation._ As the preceding argument turns very much upon the practical importance of the scale which we have been discussing, first as the single octave from the original Hypatê to Nêtê, then in its enlarged form as the Perfect System, it may be worth while to show that some such scale is implied in the history of the Greek musical notation.