Hamlet, Prince Of Denmark - V:2.2.240

GUILDENSTERN Prison, my lord?

HAMLET Denmark's a prison.

ROSENCRATZ Then is the world one.

HAMLET A goodly one, in which there are many confines, wards, and dungeons; Denmark being one o'th'worst.

ROSENCRATZ We think not so my lord.

HAMLET Why then 'tis none to you, for there is nothing either good or bad byt thinking makes it so. To me it is a prison.

ROSENCRATZ Why then your ambition makes it one; 'tis too narrow for your mind.

HAMLET O God, I could be bounded in a nutshell, and count myself a king of infinite space, were it not that I have bad dreams.

GUILDENSTERN Which dreams indeed are ambition, for the very substance of the ambitious is merely the shadow of a dream.

HAMLET A dream itself is but a shadow.

ROSENCRATZ Truly, and I hold ambition of so airy and light a quality that it is but a shadow's shadow.