made consonant to reason--'a Dorian harmony,' he adds--playing upon the musical sense of the word--'not an Ionian, certainly not a Phrygian or a Lydian, but that one which only is truly Hellenic' ([Greek: atechnôs Dôristi, all' ouk Iasti, oiomai de oude Phrygisti oude Lydisti, all' hê per monê Hellênikê estin harmonia]). The exclusion of Phrygian may be due to the fact that the virtue discussed in the _Laches_ is courage; but it is in agreement with Aristotle's opinion. The absence of Aeolian from both the Platonic passages seems to show that it had gone out of use in his time (but cp. p. 11). The point of view from which Plato professes to determine the right modes to be used in his ideal education appears clearly in the passage of the _Republic_. The modes first rejected are those which are high in pitch. The Syntono-lydian or 'high-strung Lydian' is shown by its name to be of this class. The Mixo-lydian is similar, as we shall see from Aristotle and other writers. The second group which he condemns is that of the 'slack' or low-pitched. Thus it is on the profoundly Hellenic principle of choosing the mean between opposite extremes that he approves of the Dorian and Phrygian pitch. The application of this principle was not a new one, for it had been already laid down by Pratinas: [Greek: mête syntonon diôke mête tan aneimenan]. The three chapters which Aristotle devotes to a discussion of the use of music in the state (_Politics_ viii. cc. 5-7), and in which he reviews and criticises the Platonic treatment of the same subject, will be found entirely to bear out the view now taken. It is also supported by the commentary of Plutarch, in his dialogue on Music (cc. 15-17), of which we shall have something to say hereafter. Meanwhile, following the chronological order of our authorities, we come next to the fragment of Heraclides Ponticus already mentioned (Athen. xiv. p. 624 _c_-626 _a_). § 6. _Heraclides Ponticus._