Of all plots and actions the episodic are the worst. By an episodic plot I mean one in which the sequence of the episodes is not determined by probability or necessity. Actions of this sort are composed by bad poets through their own fault, and by good ones on account of the players; for as they compose for competitive presentation, and stretch a plot beyond its capacity, they are often compelled to twist the sequence.[30] The essential dramatic force, then, is sequence, steady onward movement to a convincing issue. Scenes merely episodic, however vivid or clever each may be in itself, weaken this essential force. The episodic fault, whether it arise from weakness in the composer or from an actor’s insistence on having a “part” to suit himself rather than to suit the play, makes the worst plays because it is a fault at the source. Finally on cogency of plot depend the tragic pity and fear. The catharsis depends on our feeling the issue to be inevitable. Unexpected to the actors it may be, and most strikingly; but it cannot be fortuitous. While it is surprising to them, it must be satisfying to us as the outcome of their action. Considering the imitation as not only of a complete action, but also of events arousing fear and pity, we find these too at their height when they are [at once] unexpected [by the _dramatis personæ_] and consequential. For so we shall be more struck than by what happens of itself or by chance.[31] [“Reversal[32]” or “recognition,”[33] Aristotle goes on in chapters x and xi, if the plot is so far complicated, must arise from the plot itself, not be merely added.] Two parts of the plot, then, reversal and discovery, are such as has been shown; a third is [actual] suffering ... action destructive or painful, such as deaths on the stage, tortures, wounds, and the like.[34] This latter passage is tantalizingly brief. So far as the context shows, _suffering_ is used here to denote single scenes of unusually violent action. Why should such a scene be called a “part of the plot”? The word πάθος is used generally—and in the plural it is used repeatedly throughout the earlier chapters of this work—to mean emotion. Emotion is not a part of the plot in the sense that reversal or recognition may be a part. Rather it is a pervasive principle and an object. _Suffering_, to translate the singular noun so, may be regarded as a part of the plot in the sense that it may be an element of tragedy. So taking it, we may suppose Aristotle to countenance here such scenes of violence as were more familiar on the Elizabethan stage than on the Greek.[35] At any rate, Aristotle here inserts a chapter[36] on the formal parts (prologue, episode, exodus, etc.), before proceeding with the methods by which the plot may be worked out.