Sam thinks you can solve the puzzle of false belief by merely distinguishing between (1) and (2).
(1) Possibly some of my beliefs are false.
(2) Necessarily I do not believe any of my beliefs are false.
I think, however, that Sam is being inconsistent and, thus, he must be wrong. Consider the following cases.
(4) Possibly some houses are red.
(5) Necessarily I do not believe any houses are red.
If I endorse (5) then I cannot accept (6), because in order to do so I would have to believe some houses are red.
(6) There are red houses.
If I cannot accept (6) it is because I exclude the possibility that (6) is true. But, if such is the case, then I cannot accept (4) at all. Thus, (7) is true.
(7) I cannot accept the possibility that some houses are red.
Mutatis mutandis, if I accept (2) I exclude the possibility that (8) is true.
(8) I have false beliefs.
If so, then I cannot accept (1) at all. Thus, (9) is true.
(9) I cannot accept the possibility that some of my beliefs are false.
Briefly speaking, if I accept (2) I cannot accept (1). Furthermore, if Sam is right and (2) is uncontroversial, then it is also uncontroversial that (1) is unacceptable. Hence, Sam’s uncontroversial solution to the puzzle doesn’t work at all.
