Morality and the Foundations of Practical Reason‪.‬

1. The Requirement to Strive for Truth The normativity of practical reason derives at least partly from morality. The reason is that the norms of practical reason must include a requirement to strive to ensure that both one's relevant beliefs and one's relevant belief-like propositional attitudes are true; the only plausible justification for this requirement is a moral one. It may seem artificial to make a distinction between beliefs and belief-like propositional attitudes. However, the importance of the distinction will become clear as the argument unfolds. It will unfold as follows. First, I shall argue that this particular norm is a necessary element in any plausible set of norms of practical reason. I shall enumerate the possible types of justifications for it, and immediately eliminate the possibility that it is a matter of the antecedents of belief. Second, I shall argue that an effective norm of practical reason cannot be based on the contention that it is logically true that beliefs ought to be true. In other words, it cannot be based on the intrinsic properties of beliefs. Third, I shall argue that a rational person need not commit himself to believing truly in all cases. Instead, he might commit himself to believing that which will promote successful action. In fact, I will argue that the latter commitment is more rational than the former. Fourth, I shall examine potential consequentialist justifications. I shall argue that only the one that appeals to moral considerations can provide an adequate foundation for a requirement to strive to believe truly.