It is common, though perhaps not correct, to think that practical rationality is strictly instrumental.1 The functions of instrumental reason include finding suitable means to our determinate ends, helping to determine our indeterminate ends, and implementing our principles in appropriate actions. One reason that might be given for adopting instrumentalism with respect to rationality might be that our best scientific evidence offers little support for the idea that our brains have powers to detect good and bad as such in persons, (...) actions, or lives. But whatever one’s reasons for taking up instrumentalism, it remains to specify the relationship means are to have with ends. A natural demand is that instrumentally rational actions implement the best means to one’s given ends. Optimizing conceptions of rationality endorse this demand. A competing conception of rationality—the satisficing conception—weakens this requirement and permits some rational actions to implement (merely) satisfactory means to the agent’s given ends. The present article argues that instrumentalist theories of rationality as commonly understood cannot consistently accommodate this satisficing conception of rationality. (shrink)