 Ought and may are understood to be strict notions. By contrast, reason is a pro tanto or contributory notion. Having reason to \(\Phi\) is compatible with simultaneously having reason not to \(\Phi\) and indeed with it being the case that I ought not to \(\Phi\). Reasons, unlike oughts, may be weighed against each other; the side that wins out determines what ought to be done. Finally, I am here treating all deontic modals as propositional operators. This too is not uncontroversial. Peter Geach (1982) and more recently Mark Schroeder (2011) have argued that so-called deliberative or practical oughts are best analyzed not as operators acting on propositions but rather as expressing relations between agents and actions. (Interestingly, MacFarlane (2014: Ch. 11) has recently followed suit.) Nevertheless, I will assume without argument that the operator-reading can be made to work even in the case of deliberative oughts. For defenses of this position see e.g., Broome 2000, 2013; Chrisman 2012; and Wedgwood 2006. We can capture the particular connection between an agent and the obligation she has towards a proposition at a particular time, by indexing the operator: \(O_{S, t}\). I will drop the indices in what follows.