the idea that individuals are primarily responsible for the harm which their actions are sufficient to produce without the intervention of others or of extraordinary natural events is important, not merely to law and morality, but to the preservation of something else of great moment in human life. This is the individual's sense of himself as a separate person whose character is manifested in such actions. Individuals come to understand themselves as distinct persons, to whatever extent they do, and to acquire a sense of self-respect largely by reflection on those changes in the world about them which their actions are sufficient to bring about without the intervention of others and which are therefore attributable to them separately.