Second, Searle believes we can rationally do things that don't result from our own desires. It is widely believed that one cannot derive an "ought" from an "is", i.e. that facts about how the world is can never tell you what you should do ('Hume's Law'). By contrast, in so far as a fact is understood as relating to an institution (marriage, promises, commitments, etc.), which is to be understood as a system of constitutive rules, then what one should do can be understood as following from the institutional fact of what one has done; institutional fact, then, can be understood as opposed to the "brute facts" related to Hume's Law. For example, Searle believes the fact that you promised to do something means you should do it, because by making the promise you are participating in the constitutive rules that arrange the system of promise making itself, and therefore understand a "shouldness" as implicit in the mere factual action of promising. Furthermore, he believes that this provides a desire-independent reason for an action—if you order a drink at a bar, you should pay for it even if you have no desire to. This argument, which he first made in his paper, "How to Derive 'Ought' from 'Is'" (1964), remains highly controversial, but even three decades later Searle continued to defend his view that "...the traditional metaphysical distinction between fact and value cannot be captured by the linguistic distinction between 'evaluative' and 'descriptive' because all such speech act notions are already normative."