With the objective/subjective and normative/motivating distinctions on board, we can begin to understand the relationship that holds between reasons and ought claims. My thesis is that epistemic norms earn their authority from normative reasons that underlie them. Belief norms earn their authority from normative reasons for belief, and action norms earn their authority from normative reasons for action. These claims will only be illuminating if we already have some grip on what makes a certain consideration a reason for belief as opposed to a reason for some other attitude or action. Pamela Heironymi recently developed an influential account of reasons for belief according to which reasons are considerations that bear on the question “whether p”.67 Within the context of doxastic deliberation, wherein an agent is trying to figure out what to believe, the relevant
considerations are those that would help them answer the question “whether p”. For example, if p is the proposition “Climate change is anthropogenic”, then the reasons for believing p are the considerations that would help us answer the question of whether climate change is anthropogenic. This would include facts such as “changes in CO2 concentrations are linked to the recent proliferation of power plants” and “carbon sinks
are unable to accommodate ramped up emissions”.
The underlying justification of actional norms is importantly different from belief norms. Actional norms are supported by reasons for action. Reasons for action call for agents to perform certain actions given the circumstances and other relevant facts about the agent, such as what her desires or plans happen to be. Again, following Heironymi, reasons for action are helpfully understood as considerations that bear on the question of whether to Φ, where Φ is an action. On this way of drawing the distinction between the two reason types, it is clear why reasons for action are important in practical deliberation. For example, when an agent is concerned with how to conduct herself given the risks posed by climate change, the relevant considerations are those that tell for or against doing things like buying a hybrid car and supporting climate-friendly public policies.
The interplay between reasons for action and reasons for belief is subtle and interesting. For instance, an agent who is deliberating about how to act will, if she is at least weakly rational, want to have true beliefs about the relevant alternatives. So settling the question of whether to act requires settling all sorts of questions about whether this or that proposition is true. So when deliberating about whether to buy a hybrid, one must first settle the question of whether to believe that climate change is anthropogenic. Considerations like “changes in CO2 concentrations are linked to the recent proliferation of power plants” are relevant for settling whether to believe that climate change is anthropogenic. As such these considerations are reasons for belief. But, since the belief that is supported by this consideration is relevant for settling the question of whether to buy a hybrid, then it might be thought that “changes in CO2 concentrations are linked to the recent proliferation of power plants” also count as a reason for buying a hybrid. As
such it would also count as a reason for action. It might be thought, therefore, that there is no significant difference between reasons for belief and reasons for action that could ground the distinction I am attempting to draw between epistemic norms governing belief and actional norms governing actions that have epistemic upshots.
The distinction between reasons for belief and reasons for action can be re-
established by noting that, in the case described, the consideration that seemed to be both a reason for belief and a reason for action was relevant to the question of whether p, and the fact that p was relevant to the question of whether to act in a certain way. The consideration that “changes in CO2 concentrations are linked to the recent proliferation of power plants” is relevant to the question of whether to buy a hybrid in a mediated way – it is relevant to the question of whether to believe climate change is anthropogenic, and this fact is what is relevant to the question of whether to buy a hybrid. If CO2
concentrations had nothing to do with the question of whether climate change is
anthropogenic, then it would not be a reason for buying a hybrid. Also, if the belief that climate change is anthropogenic was not relevant to the question of whether to buy a hybrid, then the consideration that “changes in CO2 concentrations are linked to the recent proliferation of power plants” would not count as a reason for buying a hybrid. Some considerations seem to pull double duty by counting as reasons for belief and then also as reasons for action when the belief is relevant to whether the agent should act. But the sense in which these considerations are reasons for action is derivative. These
considerations seem to pull double duty only because they are reasons for holding beliefs, and these beliefs are non-derivatively relevant for a given action.