U can provide justifying reason without supplying motivating reason 3. Here Mill is an externalist with regard to moral motivation 4. U is a criterion of moral justification for action, not an explanatory device 5. There is a natural and historical basis for motivation by U 3. Human beings are social beings 4.
Humans are more and more motivated by their concern for the general welfare.
U is useless as a principle of deliberation 2. Typically, circumstances of action make it impossible to compute utility before acting 3. U need not be action guiding to be true as a moral principle 2. Habit and experience may be sufficient to guide action 3. Heroic Action Is Impossible 1.