Vices, Seneca warns, are contagious: They spread, quickly and unnoticed, from those who have them to those with whom they come into contact.2 Epictetus echoes this warning: Spend time with an unclean person, and we will become unclean as well.3 In particular, if we associate with people who have unwholesome desires, there is a very real danger that we will soon discover similar desires in ourselves, and our tranquility will thereby be disrupted.
