Hamlet's Metaphysics

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

3.1: Thus conscience does make cowards of us all, And thus the native hue of resolution Is sicklied o'er with the pale cast of thought, And enterprises of great pitch and moment, With this regard their current turn awry, And lose the name of action.

3.4: O, step between her and her fighting soul! Conceit (imagination) in weakest bodies strongest works. Speak to her, Hamlet.

5.2: Sir, in my heart there was a kind of fighting That would not let me sleep. Methought I law Worse than the mutines in the bilboes. Rashly (And praised be rashness for it) let us know, Our indiscretion sometime serves us well When our deep lots do pall, and that should learn us There's a divinity that shapes our ends, Rough-hew them how we will.

2.2: 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.

Claudius, 3.4: My words fly up, my thoughts remain below. Words without thoughts never to heaven go.