" Protecting people, saving their lives, how do you judge that; bad or good? Those fourteen on the hill? You on that there bridge? What were you doing? Good or bad?'
'I don't know' said Geralt with effort. 'I don't know, Yurga. Sometimes it seems to me that I know. And sometimes I have doubts. Would you like your son to have doubts like that?'
'Why not?' the merchant said gravely. 'He might as well. For it's a human and good thing.'
'What?'
'Doubts. Only evil, sir, never has any. "

― Andrzej Sapkowski