There are three levels of instrumental rationality, in order of decreasing thickness:
- Rationality with regard to genuine ends that one has. Some of these ends may be self-given and others may be ends that one has independently of what one desires and pursues.
- Rationality with respect to what one desires or what are goals of one's pursuits.
- Rationality with respect to arbitrary states of affairs. Thus, if a student fails an exam, that is rational with respect to the state of affairs of getting a low grade in the course, whether or not that state of affairs is one the student pursues, desires or should pursue or desire.
The thinnest option does not make actions even be prima facie rational. My sticking a pin in my nose is instrumentally rational in the third sense with respect to creating pain in myself, but is not even even prima facie rational. The third option only makes actions prima facie conditionally rational, provided that the state of affairs is one that is at least prima facie rational to pursue.
More controversially, I think the same is true of the middle option. That I pursue E and C appropriately promotes E only makes it even prima facie rational to pursue C when pursuing E is at least prima facie rational. That I have set myself to pursue a goal does not automatically make that goal be a genuine end of mine. And what I said about pursuit goes over, even more controversially, for for desires. So the middle option only gives conditional prima facie rationality: pursuing C is prima facie rational provided that pursuing E is.
One might think: "provided that pursuing or desiring E is." But there may be cases where desiring E is rational but pursuing E is not even prima facie rational. Suppose you will kill me unless I desire to step on a point-up tack. I form this desire quite rationally, but this rational desire does not give me a reason to step on the tack, given that I continue to believe that the action is not worth pursuing.
It is only the first kind of instrumental rationality that is a genuine form of rationality, that makes actions at least prima facie rational. In fact, the thinnest and medium options don't have any normativity to them at all: they just tell us about causal and logical connections between events in the world (thinnest) or events in the world and mental states (medium).