In my argument in this paper I shall assume rather than try to prove the proposition, surely not on the face of it an unreasonable one, that the question of what actions, dispositions and circumstances are such as to frustrate human beings, and what are such as to make them comparatively happy and fulfilled, has a great deal of bearing on the question of what actions and dispositions are good or bad. I shall also assume that the way in which human persons or societies can achieve fulfilment, or fail to achieve it, is explicable largely on the basis of the way in which man as a species has evolved. Few people, except those strongly affected by philosophical fashion, will wish to deny the first of these propositions. What one might call the hard utilitarian thesis, that goodness is to be defined in terms of contribution to happiness or fulfilment, may involve the ‘naturalistic fallacy’, may be vulnerable to the arguments of Moore, Hare and others. But I shall not commit myself here to the hard utilitarian thesis, since I am not insisting that goodness may be defined in terms of contribution to human happiness or fulfilment, but only that the question of how far anything contributes to human happiness or fulfilment has a vital bearing on the question of whether and to what extent it is good. I do not think that many people really doubt the truth of this proposition, unless they confuse it with the hard utilitarian thesis.