A Kantian or even a semi-Kantian cannot permit himself to value anything
profoundly, since an inexplicable “duty” may demand the sacrifice of his values
at any moment, wiping out any long-range plan or struggle he might have
undertaken to achieve them . . . .
The notion of “duty” is intrinsically anti-causal. In its origin, a “duty”
defies the principle of efficient causation—since it is causeless (or
supernatural); in its effects, it defies the principle of final
causation—since it must be performed regardless of consequences.