Editing Rationality (section)

=== Based on reason-responsiveness ===
A common idea of many theories of rationality is that it can be defined in terms of reasons. In this view, to be rational means to respond correctly to reasons.<ref name="Broome2021"/><ref name="Moser2006"/><ref name="Heinzelmann2022"/> For example, the fact that a food is healthy is a reason to eat it. So this reason makes it rational for the agent to eat the food.<ref name="Heinzelmann2022"/> An important aspect of this interpretation is that it is not sufficient to merely act accidentally in accordance with reasons. Instead, ''responding'' to reasons implies that one acts [[Intention|intentionally]] because of these reasons.<ref name="Broome2021"/>

Some theorists understand reasons as external facts. This view has been criticized based on the claim that, in order to respond to reasons, people have to be aware of them, i.e. they have some form of epistemic access.<ref name="Heinzelmann2022"/><ref name="Lord2018-1"/> But lacking this access is not automatically irrational. In one example by [[John Broome (philosopher)|John Broome]], the agent eats a fish contaminated with [[salmonella]], which is a strong reason against eating the fish. But since the agent could not have known this fact, eating the fish is rational for them.<ref name="Broome2007"/><ref name="Kiesewetter2017"/> Because of such problems, many theorists have opted for an internalist version of this account. This means that the agent does not need to respond to reasons in general, but only to reasons they have or possess.<ref name="Broome2021"/><ref name="Heinzelmann2022"/><ref name="Lord2018-1"/><ref name="Lord2018-3"/> The success of such approaches depends a lot on what it means to have a reason and there are various disagreements on this issue.<ref name="Mele2004a"/><ref name="Heinzelmann2022"/> A common approach is to hold that this access is given through the possession of [[evidence]] in the form of cognitive [[mental state]]s, like [[perception]]s and [[knowledge]]. A similar version states that "rationality consists in responding correctly to beliefs about reasons". So it is rational to bring an umbrella if the agent has strong evidence that it is going to rain. But without this evidence, it would be rational to leave the umbrella at home, even if, unbeknownst to the agent, it is going to rain.<ref name="Broome2021"/><ref name="Lord2018-3"/> These versions avoid the previous objection since rationality no longer requires the agent to respond to external factors of which they could not have been aware.<ref name="Broome2021"/>

A problem faced by all forms of reason-responsiveness theories is that there are usually many reasons relevant and some of them may conflict with each other. So while salmonella contamination is a reason against eating the fish, its good taste and the desire not to offend the host are reasons in favor of eating it. This problem is usually approached by weighing all the different reasons. This way, one does not respond directly to each reason individually but instead to their [[weighted sum]]. Cases of conflict are thus solved since one side usually outweighs the other. So despite the reasons cited in favor of eating the fish, the balance of reasons stands against it, since avoiding a salmonella infection is a much weightier reason than the other reasons cited.<ref name="Broome2007"/><ref name="Kiesewetter2017"/> This can be expressed by stating that rational agents pick the option favored by the balance of reasons.<ref name="Mele2004a"/><ref name="McClennen2004"/>

However, other objections to the reason-responsiveness account are not so easily solved. They often focus on cases where reasons require the agent to be irrational, leading to a rational dilemma. For example, if terrorists threaten to blow up a city unless the agent forms an irrational belief, this is a very weighty reason to do all in one's power to violate the norms of rationality.<ref name="Broome2021"/><ref name="Moriarty2020"/>