  A related but more metaphysical controversy would be stated thus today: what is the source or foundation of moral norms? In Hume’s day this is the question what is the ground of moral obligation (as distinct from what is the faculty for acquiring moral knowledge or belief). Moral rationalists of the period such as Clarke (and in some moods, Hobbes and Locke) argue that moral standards or principles are requirements of reason — that is, that the very rationality of right actions is the ground of our obligation to perform them. Divine voluntarists of the seventeenth and eighteenth centuries such as Samuel Pufendorf claim that moral obligation or requirement, if not every sort of moral standard, is the product of God’s will. The moral sense theorists (Shaftesbury and Hutcheson) and Butler see all requirements to pursue goodness and avoid evil as consequent upon human nature, which is so structured that a particular feature of our consciousness (whether moral sense or conscience) evaluates the rest. Hume sides with the moral sense theorists on this question: it is because we are the kinds of creatures we are, with the dispositions we have for pain and pleasure, the kinds of familial and friendly interdependence that make up our life together, and our approvals and disapprovals of these, that we are bound by moral requirements at all.