Our epistemic confidence in these commitments is so high that they function more as rules of linguistic usage than as bits of knowledge (/V 251; OC 124,136). Returning to my example, one cannot use the word “spoon” as we do without first conceding that spoons do not bite and that food is worth having. How do we know that they do not bite? Well, they just don’t. How do we know that food is worth having? Well, it just is. And if you are uncertain here, about these matters, it is not clear how we can respond. Why? Because these doubts indicate that your grasp of the concept is insufficient for ordinary conversation about spoons (OC 126). In fact, if you press your strange doubts, it is likely that the rest of us will respond by discounting either your sincerity or your basic rationality (OC 154-155,219-220).