Not just philosophers are interested in welfare. Economics is concerned, in part, with evaluating economic arrangements, and one way in which an arrangement can be evaluated is in terms of the amount of welfare it contains. Also, it is a common assumption among economists, and one codified in classical utility theory, that one state 4 of affairs is better for a person than another if and only if she prefers the former to the latter (Broome 2001). This assumption is in fact a substantive thesis about welfare.