" The logic of this metaphor is extremely important: Since diseases can spread through contact, it follows from the metaphor that immorality can spread through contact. Hence, immoral people must be kept away from moral people, lest they become immoral too. This is part of the logic behind urban flight, segregated neighborhoods, and strong sentencing guidelines even for nonviolent offenders. The same logic lies behind guilt-by-association arguments: If you are in contact with immoral people, you become immoral. M "
― George Lakoff , Moral Politics: How Liberals and Conservatives Think