  One way for monists to make sense of complexity in value choice is to point out that there are different bearers of value, and this makes a big difference to the experience of choice. (See Hurka, 1996; Schaber, 1999; Klocksiem 2011). Here is the challenge to monism in Michael Stocker’s words (Stocker, 1990, p. 272): “[if monism is true] there is no ground for rational conflict because the better option lacks nothing that would be made good by the lesser.” In other words, there are no relevant differences between the better and worse options except that the better option is better. Thomas Hurka objects that there can be such differences. For example, in a choice between giving five units of pleasure to A and ten units to B, the best option (more pleasure for B) involves giving no pleasure at all to A. So there is something to rationally regret, namely, that A had no pleasure. The argument can be expanded to deal with all sorts of choice situation: in each situation,  a monist can say something sensible about an unavoidable loss, a loss that really is a loss. If, of two options one will contribute more basic value, the monist must obviously choose that one. But the lesser of the options may contribute value via pleasure, while the superior option contributes value via knowledge, and so there is a loss in choosing the option with the greater value contribution—a loss in pleasure— and it is rational for us to regret this.