Why One Basic Principle?

Principle monists believe that our moral duties, such as fidelity and non-maleficence, can be justified in terms of one basic moral principle. Principle pluralists disagree, some suggesting that only an excessive taste for simplicity or a desire to mimic natural science could lead one to endorse monism. In Ideal Code, Real World (Oxford, 2000), Brad Hooker defends a monist theory, employing the method of reflective equilibrium to unify the moral duties under a version of rule consequentialism. Hooker's arguments have drawn powerful criticisms from pluralists such as Alan Thomas, Phillip Montague and Philip Stratton-Lake. Against these critics, I argue that Hooker's monism enjoys certain practical advantages associated with the simplicity of a single basic principle. These advantages are often overlooked because they appear primarily in cases of second-order deliberation, in which one must decide whether our basic moral duties support a certain derivative duty. I argue that these advantages of monism over pluralism are analogous to the advantages that generalists claim over moral particularism. Because pluralists are generalists, I conclude that they are in an awkward dialectical position to dismiss Hooker's monism for the reasons they usually offer.