Praxeological thinking is equally valid regardless of whether the utility scales being maximized are based on selfishness, altruism, intellectuality, spirituality, or materialism. For instance, the law of diminishing marginal utility applies universally to Crusoe's factors of production, regardless of whether he builds his tree house for his own shelter and protection, for homeless members of a tribe of natives, or as a temple where he can seek nirvana through self-immolation. To evaluate such alternative purposes is the province of ethics. Praxeology, in contrast, examines human action in general, abstracted from the specific purposes of acting individuals. Its approach is distinct from ethics and broader than psychology.