We assume that, for the finest form of Tragedy, the Plot must be not
simple but complex; and further, that it must imitate actions arousing
pity and fear, since that is the distinctive function of this kind of
imitation. It follows, therefore, that there are three forms of Plot
to be avoided. (1) A good man must not be seen passing from happiness
to misery, or (2) a bad man from misery to happiness.

The first situation is not fear-inspiring or piteous, but simply
odious to us. The second is the most untragic that can be; it has no
one of the requisites of Tragedy; it does not appeal either to the
human feeling in us, or to our pity, or to our fears. Nor, on the
other hand, should (3) an extremely bad man be seen falling from
happiness into misery. Such a story may arouse the human feeling in
us, but it will not move us to either pity or fear; pity is occasioned
by undeserved misfortune, and fear by that of one like ourselves; so
that there will be nothing either piteous or fear-inspiring in the
situation. There remains, then, the intermediate kind of personage, a
man not pre-eminently virtuous and just, whose misfortune, however, is
brought upon him not by vice and depravity but by some error of
judgement, of the number of those in the enjoyment of great reputation
and prosperity; e.g. Oedipus, Thyestes, and the men of note of similar
families. The perfect Plot, accordingly, must have a single, and not
(as some tell us) a double issue; the change in the hero's fortunes
must be not from misery to happiness, but on the contrary from
happiness to misery; and the cause of it must lie not in any
depravity, but in some great error on his part; the man himself being
either such as we have described, or better, not worse, than that.
Fact also confirms our theory. Though the poets began by accepting any
tragic story that came to hand, in these days the finest tragedies are
always on the story of some few houses, on that of Alemeon, Oedipus,