of one is sometimes defeated by the frolick of another; and many
mischiefs and many benefits are done and hindered without design.

Out of this chaos of mingled purposes and casualties the ancient
poets, according to the laws which custom had prescribed, selected
some the crimes of men, and some their absurdities; some the
momentous vicissitudes of life, and some the lighter occurrences;
some the terrours of distress, and some the gayeties of prosperity.
Thus rose the two modes of imitation, known by the names of tragedy
and comedy, compositions intended to promote different ends by
contrary means, and considered as so little allied, that I do not
recollect among the Greeks or Romans a single writer who attempted
both.

Shakespeare has united the powers of exciting laughter and sorrow
not only in one mind, but in one composition. Almost all his plays
are divided between serious and ludicrous characters, and, in the
successive evolutions of the design, sometimes produce seriousness
and sorrow, and sometimes levity and laughter.

That this is a practice contrary to the rules of criticism will be
readily allowed; but there is always an appeal open from criticism
to nature. The end of writing is to instruct; the end of poetry
is to instruct by pleasing. That the mingled drama may convey all
the instruction of tragedy or comedy cannot be denied, because
it includes both in its alterations of exhibition, and approaches
nearer than either to the appearance of life, by shewing how
great machinations and slender designs may promote or obviate one
another, and the high and the low co-operate in the general system
by unavoidable concatenation.