If it were done when 'tis done, then 'twere wellIt were done quickly: if the assassinationCould trammel up the consequence, and catchWith his surcease success; that but this blowMight be the be-all and the end-all here,But here, upon this bank and shoal of time,We'ld jump the life to come. But in these casesWe still have judgment here; that we but teachBloody instructions, which, being taught, returnTo plague the inventor: this even-handed justiceCommends the ingredients of our poison'd chaliceTo our own lips. He's here in double trust;First, as I am his kinsman and his subject,Strong both against the deed; then, as his host,Who should against his murderer shut the door,Not bear the knife myself. Besides, this DuncanHath borne his faculties so meek, hath beenSo clear in his great office, that his virtuesWill plead like angels, trumpet-tongued, againstThe deep damnation of his taking-off;And pity, like a naked new-born babe,Striding the blast, or heaven's cherubim, horsedUpon the sightless couriers of the air,Shall blow the horrid deed in every eye,That tears shall drown the wind. I have no spurTo prick the sides of my intent, but onlyVaulting ambition, which o'erleaps itselfAnd falls on the other.
Friar Laurence:O, mickle is the powerful grace that liesIn herbs, plants, stones, and their true qualities: For nought to vile that on the earth doth live, But to the earth some special good doth give; nor aught so good, but, strain'd from that fair use, Revolts from true birth, stumbling on abuse: Virtue itself turns vice, being misapplied, And vice sometime's by action dignified.