The author presents and defends three theses: (1) "the first is that it is not profitable for us at present to do moral philosophy; that should be laid aside at any rate until we have an adequate philosophy of psychology." (2) "the second is that the concepts of obligation, And duty... And of what is morally right and wrong, And of the moral sense of 'ought', Ought to be jettisoned if this is psychologically possible...." (3) "the third thesis is that (...) the differences between the well-Known english writers on moral philosophy from sidgwick to the present day are of little importance." (staff). (shrink)

To what extent can philosophical thought experiments reveal norms? Some ethicists have argued that certain thought experiments reveal that people draw a morally significant distinction between "doing" and "allowing". I examine one such thought experiment in detail and argue that the intuitions it elicits can be explained by "prospect theory", a psychological theory about the way people reason. The extent to which such alternative explanations of the results of thought experiments in philosophy are generally available is an empirical question.