The use (204) of rhythm is most extensive in panegyric (207); in the other fields it enters when panegyric enters, or when statement of facts demands rather dignity than poignancy, often also in amplification, and most frequently in the peroration (210). For variety change (211) from the statements grouped and rounded in periods to statements detached (_incisa_ and _membra_). Debate, more than exposition, needs speed. The cadence, or close (_clausula_, 215) may be in any one of several modes. The dichoreus, preferred in Asia (212), is admirable; but any one cadence palls. A full period (221) consists of four parts, or clauses (_membra_), i.e., is about the length of four hexameter verses; and is held together by _nodi continuationis_. When we wish to shift to detached short sentences (_membratim_), as we must often do in forensic, we pause, and break the rhythm that might suggest artifice. But even in such shorter reaches (223) we need rhythm, whether they be _incisa_, _membra_, or short periods; and these may be supported by a longer period, ending in a dichoreus or a spondee. The shorter reaches demand freer measures. They are of most force in forensic (225), especially in proof and refutation. Nor is any sort of speaking (226) stronger than to strike with two or three words, sometimes even with one, and then to interpose a rhythmical period. Rhythm is not merely beautiful (227), but, like the beautiful motions of athletes, useful. Pursuit of it must avoid the appearance of artifice, padding (231) to round the cadence, the laming of the movement by too many short reaches, and monotony. Proof of the value of rhythm may be made by dislocating[96] the sentence movement of a good orator without changing the words, or conversely by rearranging the sentences of a careless orator (233). Those who affect to despise rhythm (234) are unable to master it. Calling themselves Attic, they ignore the rhythm of Demosthenes. If they prefer a loose style, let them follow it if they can show even in their parts the beauty that is lacking in the whole (235), or if they can compose in any other style; but the perfect orator (236) is master of all his art.