We should expect to find that, to produce this effect, it was necessary to depart frequently from natural forms of expression, either by changing the usual order, or by inserting unnecessary words. It is probable that Isocrates resorted to both these devices; but such is the skill with which he handles his materials that careful reading is necessary to detect the distortions.[188] Dionysius further notes that dissonance or clashing of consonants is rare, and herein Isocrates seems to have been at pains to follow the rules of euphony laid down in his own Τέχνη. In a fragment preserved by Hermogenes he tells his readers to avoid the repetition of the same syllable in consecutive words—as ἡλικὰ καλά, ἔνθα Θαλῆς.[189] The ingenuity of Blass has discovered passages in which the natural form of a phrase has been altered to avoid such juxtaposition of similar syllables.[190] Certain combinations of consonants, too, are hard to pronounce, and must therefore be avoided. There is, in truth, much justice in the remark of Dionysius that in reading Isocrates it is not the separate words but the sentence as a whole that we must take into account. The third characteristic of Isocrates’ style is his attention to rhythm. The extravagance of Gorgias had hindered the development of the language by introducing into prose the rhythms and language of poetry; Thrasymachus, as we know from Aristotle’s _Rhetoric_, had studied the effect of the foot ‘_paeonius_’ (–⏑⏑⏑ or ⏑⏑⏑–) at the beginning and end of periods.[191] Isocrates, while deprecating the use of poetical metres in any strict sense, asserted that oratorical prose should have rhythms of its own, and favoured combinations of the trochee and the iambus. In this he differed from Aristotle, who disapproved of the iambic rhythm as being too similar to the natural course of ordinary speech, and of the trochaic, as being too light and tripping—in contrast to the hexameter, which he classed as too solemn for spoken language.[192] The periods of Isocrates are remarkable for their elaboration. The analyses of Blass show us a complication of structure in some of the longer sentences which may almost be compared to that of a Pindaric ode. Never, perhaps, has there been a writer who attained such luxuriant complexity in his composition of sentences. But Isocrates is too much the slave of his own virtues; his periods are so long, so complete, so uniformly artistic, that their everlasting procession is monotonous. Lysias, less perfect in form, has in consequence more variety; Demosthenes, who could compose long periods, did not confine himself to them, but enlivened his style by contrast.