necessary or probable connection: but he made the Odyssey, and
likewise the Iliad, to center round an action that in our sense of the
word is one. As therefore, in the other imitative arts, the
imitation is one when the object imitated is one, so the plot, being
an imitation of an action, must imitate one action and that a whole,
the structural union of the parts being such that, if any one of
them is displaced or removed, the whole will be disjointed and
disturbed. For a thing whose presence or absence makes no visible
difference, is not an organic part of the whole.
POETICS|9

  IX

  It is, moreover, evident from what has been said, that it is not the
function of the poet to relate what has happened, but what may happen-
what is possible according to the law of probability or necessity. The
poet and the historian differ not by writing in verse or in prose. The
work of Herodotus might be put into verse, and it would still be a
species of history, with meter no less than without it. The true
difference is that one relates what has happened, the other what may
happen. Poetry, therefore, is a more philosophical and a higher
thing than history: for poetry tends to express the universal, history
the particular. By the universal I mean how a person of a certain type
on occasion speak or act, according to the law of probability or
necessity; and it is this universality at which poetry aims in the
names she attaches to the personages. The particular is- for
example- what Alcibiades did or suffered. In Comedy this is already
apparent: for here the poet first constructs the plot on the lines
of probability, and then inserts characteristic names- unlike the
lampooners who write about particular individuals. But tragedians
still keep to real names, the reason being that what is possible is
credible: what has not happened we do not at once feel sure to be
possible; but what has happened is manifestly possible: otherwise it
would not have happened. Still there are even some tragedies in
which there are only one or two well-known names, the rest being
fictitious. In others, none are well known- as in Agathon's Antheus,
where incidents and names alike are fictitious, and yet they give none
the less pleasure. We must not, therefore, at all costs keep to the
received legends, which are the usual subjects of Tragedy. Indeed,
it would be absurd to attempt it; for even subjects that are known are
known only to a few, and yet give pleasure to all. It clearly
follows that the poet or 'maker' should be the maker of plots rather
than of verses; since he is a poet because he imitates, and what he
imitates are actions. And even if he chances to take a historical
subject, he is none the less a poet; for there is no reason why some
events that have actually happened should not conform to the law of
the probable and possible, and in virtue of that quality in them he is
their poet or maker.

  Of all plots and actions the episodic are the worst. I call a plot
'episodic' in which the episodes or acts succeed one another without
probable or necessary sequence. Bad poets compose such pieces by their
own fault, good poets, to please the players; for, as they write
show pieces for competition, they stretch the plot beyond its
capacity, and are often forced to break the natural continuity.

  But again, Tragedy is an imitation not only of a complete action,
but of events inspiring fear or pity. Such an effect is best
produced when the events come on us by surprise; and the effect is
heightened when, at the same time, they follows as cause and effect.
The tragic wonder will then be greater than if they happened of
themselves or by accident; for even coincidences are most striking
when they have an air of design. We may instance the statue of Mitys
at Argos, which fell upon his murderer while he was a spectator at a
festival, and killed him. Such events seem not to be due to mere
chance. Plots, therefore, constructed on these principles are
necessarily the best.
POETICS|10

  X

  Plots are either Simple or Complex, for the actions in real life, of
which the plots are an imitation, obviously show a similar
distinction. An action which is one and continuous in the sense
above defined, I call Simple, when the change of fortune takes place
without Reversal of the Situation and without Recognition

  A Complex action is one in which the change is accompanied by such
Reversal, or by Recognition, or by both. These last should arise
from the internal structure of the plot, so that what follows should
be the necessary or probable result of the preceding action. It
makes all the difference whether any given event is a case of
propter hoc or post hoc.
POETICS|11

  XI

  Reversal of the Situation is a change by which the action veers
round to its opposite, subject always to our rule of probability or
necessity. Thus in the Oedipus, the messenger comes to cheer Oedipus
and free him from his alarms about his mother, but by revealing who he
is, he produces the opposite effect. Again in the Lynceus, Lynceus
is being led away to his death, and Danaus goes with him, meaning to
slay him; but the outcome of the preceding incidents is that Danaus is
killed and Lynceus saved.

  Recognition, as the name indicates, is a change from ignorance to
knowledge, producing love or hate between the persons destined by
the poet for good or bad fortune. The best form of recognition is
coincident with a Reversal of the Situation, as in the Oedipus.