ancient critics, and contrary to all their experience, it is evident
that Plato must have fixed the eye of his contemplation on the innermost
essentials of the drama, abstracted from the forms of age or country. In
another passage he even adds the reason, namely, that opposites
illustrate each other's nature, and in their struggle draw forth the
strength of the combatants, and display the conqueror as sovereign even
on the territories of the rival power.

Nothing can more forcibly exemplify the separative spirit of the Greek
arts than their comedy as opposed to their tragedy. But as the immediate
struggle of contraries supposes an arena common to both, so both were
alike ideal; that is, the comedy of Aristophanes rose to as great a
distance above the ludicrous of real life, as the tragedy of Sophocles
above its tragic events and passions;--and it is in this one point, of
absolute ideality, that the comedy of Shakspeare and the old comedy of
Athens coincide. In this also alone did the Greek tragedy and comedy
unite; in every thing else they were exactly opposed to each other.
Tragedy is poetry in its deepest earnest; comedy is poetry in unlimited
jest. Earnestness consists in the direction and convergence of all the
powers of the soul to one aim, and in the voluntary restraint of its
activity in consequence; the opposite, therefore, lies in the apparent
abandonment of all definite aim or end, and in the removal of all bounds
in the exercise of the mind,--attaining its real end, as an entire
contrast, most perfectly, the greater the display is of intellectual
wealth squandered in the wantonness of sport without an object, and the
more abundant the life and vivacity in the creations of the arbitrary
will.

The later comedy, even where it was really comic, was doubtless likewise
more comic, the more free it appeared from any fixed aim.