 Jones’s stated aim in “Practical Dualism” is to “deduce” the rule of prudence (or rational self-interest) from benevolence (Jones 1917–18, 323): “The reasonableness of benevolence implies the reasonableness of self-love” (1920, 504). The upshot is that we have reduced our fundamental principles to one, thus solving the problem of the dualism of two methods. 