For Alex Drake (lady_bols):

"She heard him mutter, 'Can you take away this grief?'
'I'm sorry,' she replied quietly. 'Everyone asks me. And I would not do so even if I knew how. It belongs to you. Only time and tears take away the grief; that is what they are for.'" 
~Terry Pratchett

For Sherlock (hello_freak):

"A mind all logic is like a knife all blade. It makes the hand bleed that uses it." ― Rabindranath Tagore

For John Silver(an_honest_man):

"There is thy gold, worse poison to men's souls,
Doing more murder in this loathsome world,
Than these poor compounds that thou mayst not sell."
― William Shakespeare, Romeo and Juliet

For Bryan Mills (particularskill):

"Courage is grace under pressure."
― Ernest Hemingway