Reason fundamentalism and what is wrong with it

Is there a fundamental feature of normativity, to which other features can be reduced? One defensible view is that the fundamental feature is the relation that holds between a person and F-ing when the person has reason to F. ("F" stands for any verb phrase, such as "run for the bus" or "hope for relief" or "believe Kampala is in Ghana.") Another defensible view is that the fundamental feature is the relation that holds between a person and F-ing when the person ought to F. The popular view that the fundamental feature of normativity is the property of being a reason is not defensible, since that property can be reduced to either of the two relations I described. I argue that the second of these views-"ought fundamentalism"-is more credible that the first-"reason fundamentalism"-because it is more faithful to our ordinary normative concepts.