Sunday, June 12, 2005
Six views about reasons
First, let me assert a common distinction and introduce a terminological convention in order to deal with it. In everyday talk when we provide explanations in terms of reasons there are two apparently different things that we might mean. On the one hand, we might be providing what I will henceforth call an explanation. An explanation is an account of an event which, if successful, provides a true description of the event. So, if someone were to say, "The reason you hear thunder after you see the lightning is that light travels faster than sound" then this would be a successful explanation. On the other hand, we might instead be making a normative claim or a claim about an agent's motivations. So, for example, we might say "The reason that John left is that he was offended." I'm going to limit the use of the term reason to apply to cases of this second sort.
Another terminological convention will be to refer to whatever is a candidate for being a reason as a consideration.
The basic distinction between internal and external reasons has to do with whether a consideration's status as a reason is tied to the possibility that the consideration might have motivational force for a given agent. To say that some consideration is an internal reason for an agent is to say that the consideration is capable of motivating that agent to act. To say that some consideration is an external reason for an agent is to say that it counts in favor of some action even if there is no possibility that the agent could be motivated by the consideration.
In mapping out the logical possibilities below, the hope is to say what conditions must hold in order for some consideration to be a reason proper. For the purposes of the list it is assumed that both the notion of an internal reason and that of an external reason are coherent and that it is conceivable that a consideration may count as either without being a reason proper.
Six views about reasons:
- Pure Internalism
That the consideration is an internal reason is always necessary and sufficient, but that it is an external reason is never necessary or sufficient.
- Weak Internalism
That the consideration is an internal reason is always necessary and sometimes but not always sufficient, while that it is an external reason is sometimes necessary but never sufficient.
- Strong Ecuminicism
That the consideration is both an internal and an external reason is always necessary, hence its being either is never sufficient on its own.
- Weak Ecuminicism
Both that the consideration is an internal reason and that it is an external reason is sometimes necessary and sometimes sufficent.
- Weak Externalism
That the consideration is an external reason is always necessary and sometimes but not always sufficient, while that it is an internal reason is sometimes necessary but never sufficient.
- Pure Externalism
That the consideration is an external reason is always necessary and sufficient, but that it is an internal reason is never necessary or sufficient.
1 This is the view I have previously called strong internalism. The expression pure internalism is Tiffany's and now seems to me to be a better fit.