“Kill her, take her money, on condition that you dedicate yourself with its help to the service of humanity and the common good: don’t you think that thousands of good deeds will wipe out one little, insignificant transgression? For one life taken, thousands saved from corruption and decay! One death, and a hundred lives in exchange - why, it’s simple arithmetic! What is the life of that stupid, spiteful, consumptive old woman weighed against the common good? No more than the life of a louse or a cockroach - less, indeed, because she is actively harmful.”
from Crime and Punishment by Fyodor Dostoevsky