 Still, we saw earlier that there is an important difference between Reid and Kant. Kant is an ethical monist, holding that there is one master principle of morality—the categorical imperative—which is fundamental and from which all our particular duties can be derived. Reid, by contrast, rejects ethical monism, maintaining that there is no such master principle, but only a variety of moral principles that are self-evident and irreducible to one another. The locution “the principle of duty,” in Reid’s mouth, is probably best understood to be a shorthand way of referring to one or another of these principles which can govern practical deliberation.