 But what about the problem of the Dualism of Practical Reason? In later life, Russell ceased to worry about it perhaps because he realized that it is a problem that cannot be resolved. The Cosmos of Duty really is a Chaos (as Sidgwick rather colorfully put it). Duty and Interest can come into conflict, and when they do, there is no decisive reason for preferring the one to the other. All you can do is to try to instill moral and altruistic motivations, which is what Russell tried to do with his children. But when they asked why they should care about other people (as his daughter Kate defiantly did) his response was rather lame.