Another obvious means of emphasis in the drama is the use of antithesis,--an expedient employed in every art. The design of a play is not so much to expound characters as to contrast them. People of varied views and opposing aims come nobly to the grapple in a struggle that vitally concerns them; and the tensity of the struggle will be augmented if the difference between the characters is marked. The comedies of Ben Jonson, which held the stage for two centuries after their author's death, owed their success largely to the fact that they presented a constant contrast of mutually foiling personalities. But the expedient of antithesis is most effectively employed in the balance of scene against scene. What is known as "comic relief" is introduced in various plays, not only, as the phrase suggests, to rest the sensibilities of the audience, but also to emphasise the solemn scenes that come before and after it. It is for this purpose that Shakespeare, in _Macbeth_, introduces a low-comic soliloquy into the midst of a murder scene. Hamlet's ranting over the grave of Ophelia is made more emphatic by antithesis with the foolish banter that precedes it. This contrast of mood between scene and scene was unknown in ancient plays and in the imitations of them that flourished in the first great period of the French tragic stage. Although the ancient drama frequently violated the three unities of action, time, and place, it always preserved a fourth unity, which we may call unity of mood. It remained for the Spaniards and the Elizabethan English to grasp the dramatic value of the great antithesis between the humorous and the serious, the grotesque and the sublime, and to pass it on through Victor Hugo to the contemporary theatre. A further means of emphasis is, of course, the use of climax. This principle is at the basis of the familiar method of working up an entrance. My lady's coach is heard clattering behind the scenes. A servant rushes to the window and tells us that his mistress is alighting. There is a ring at the entrance; we hear the sound of footsteps in the hall. At last the door is thrown open, and my lady enters, greeted by a salvo of applause.