her--instead of doing that, he took an action with a Unity
of the kind we are describing as the subject of the _Odyssey_, as also
of the _Iliad_. The truth is that, just as in the other imitative arts
one imitation is always of one thing, so in poetry the story, as an
imitation of action, must represent one action, a complete whole,
with its several incidents so closely connected that the transposal or
withdrawal of any one of them will disjoin and dislocate the whole. For
that which makes no perceptible difference by its presence or absence is
no real part of the whole.

9

From what we have said it will be seen that the poet's function is to
describe, not the thing that has happened, but a kind of thing that
might happen, i.e. what is possible as being probable or necessary. The
distinction between historian and poet is not in the one writing prose
and the other verse--you might put the work of Herodotus into verse, and
it would still be a species of history; it consists really in this, that
the one describes the thing that has been, and the other a kind of thing
that might be. Hence poetry is something more philosophic and of graver
import than history, since its statements are of the nature rather
of universals, whereas those of history are singulars. By a universal
statement I mean one as to what such or such a kind of man will probably
or necessarily say or do--which is the aim of poetry, though it affixes
proper names to the characters; by a singular statement, one as to what,
say, Alcibiades did or had done to him. In Comedy this has become clear
by this time; it is only when their plot is already made up of probable
incidents that they give it a basis of proper names, choosing for the
purpose any names that may occur to them, instead of writing like the
old iambic poets about particular persons. In Tragedy, however, they
still adhere to the historic names; and for this reason: what convinces
is the possible; now whereas we are not yet sure as to the possibility
of that which has not happened, that which has happened is manifestly
possible, else it would not have come to pass. Nevertheless even in
Tragedy there are some plays with but one or two known names in them,
the rest being inventions; and there are some without a single known
name, e.g. Agathon's Anthens, in which both incidents and names are of
the poet's invention; and it is no less delightful on that account. So
that one must not aim at a rig