Antithesis

Placing opposed ideas or words side by side, so that one illuminates the other through contrast.

In Hamlet

But I have that within which passeth show; / These but the trappings and the suits of woe.

Sets “within me” against “appearance,” the hidden feeling against the displayed sign. The contrast separates true grief from grief for show and makes clear on which side Hamlet stands.

Act I: The Ghost and the order of revenge, Hamlet, to Gertrude

I am thy father's spirit, / Doomed for a certain term to walk the night, / And for the day confined to fast in fires / Till the foul crimes done in my days of nature / Are burnt and purged away.

Act I: The Ghost and the order of revenge, The Ghost, to Hamlet

To be, or not to be, that is the question

Act III: The Mousetrap and the death of Polonius, Hamlet, alone, in the soliloquy

He's loved of the distracted multitude, / Who like not in their judgment but their eyes

Act IV: Exile, madness, and the trap, Claudius, to the councilors

Well, God 'ild you! They say the owl was a baker's daughter. Lord, we know what we are, but know not what we may be.

Act IV: Exile, madness, and the trap, Ophelia, mad, to Claudius