William Shakespeare (1564-1616)
In Othello, soliloquy is used mainly for the revelation of secret plans and conspiracies of lago. lago is involved in soliloquy for ten times in the play, and each time he plans how to destroy the life and happiness of others by thinking out loud to himself. He also describes himself as "I am not what I am" or his philosophy of life as the "divinity of hell" in his soliloquies. This helps Shakespeare portray his character more easily.
Another function of lago's soliloquy also seems to be dramatic. To the simple audience of Shakespeare, it would be rather difficult to understand all the cunning conspiracies of lago if he were not made to speak out his plans aloud. Besides, we also find it easy to follow the development of the drama when the manipulator discloses his future plan of villainy. This also of course adds to the suspense and dramatic tension in the drama.
As usual, the soliloquy of Othello is a poetic or a meditative element which exposes the deeper private side of the character's minds. Othello is involved in a soliloquy just before he kills his wife. That soliloquy is very poetic: he says that he will smell the rose for the last time on its tree and that it will not be possible to plant the flower back to its branch; indeed, he is emotive and excited, and also unknowingly right. Othello's soliloquy here is a means of giving expression to the complex state of his mind and feelings, as he is struggling with a problem of great importance. We find much emotional intensity in this 'meditation' over the weighty issue of having to murder his wife.
In short, the soliloquy of Othello serves the poetic functions of exposing psychologically and thematically significant material. The dark and dangerous evils of the mind of Iago and the storms in the mind of Othello could not have been so effectively revealed without their soliloquies, and their characters would not have been so powerfully delineated without their involving mind-searching soliloquies.