Nor again the passing of a thoroughly bad man from good fortune to bad fortune. Such a structure might satisfy our feelings but it arouses neither pity nor fear, the one being for the man who does not deserve his misfortune and the other for the man who is like ourselves—pity for the undeserved misfortune, fear for the man like ourselves—so that the result will arouse neither pity nor fear.
There remains then the mean between these. This is the sort of man who is not pre-eminently virtous and just, and yet it is through no badness or villainy of his own that he falls into the fortune, but rather through some flaw in him, [Note] he being one of those who are in high station and good fortune, like Oedipus and Thyestes and the famous men of such families as those.
The successful plot must then have a single [Note] and not, as some say, a double issue; and the change must be not to good fortune from bad but, on the contrary, from good to bad fortune, and it must not be due to villainy but to some great flaw in such a man as we have described, or of one who is better rather than worse.
This can be seen also in actual practice. For at first poets accepted any plots, but to-day the best tragedies are written about a few families—