Through the reduction of one theory or discipline to another, the results of the reduced theory or discipline can be obtained from the reducing one. In contrast, a theory that describes emergent phenomena is ostensibly autonomous: no other theory can be understood as providing a reducing basis. Questions of emergence and reduction determine how much one discipline can borrow from another, and, to a certain extent, what structures scientific theories in various disciplines can have. Successful reductions increase the epistemological importance of the reducing theories, and arguably their...