Is this a dagger which I see before me,
The handle toward my hand? Come, let me clutch thee.
I have thee not, and yet I see thee still.
Art thou not, fatal vision, sensible
To feeling as to sight? Or art thou but
A dagger of the mind, a false creation
Proceeding from the heat-oppressèd brain?
I see thee yet, in form as palpable
As this which now I draw.

Shakespeare
William Shakespeare (1564-1616) English dramatist and poet
Macbeth, Act 2, sc. 1, l. 44ff (2.1.44-53) (1606)
    (Source)