Reference and Spatio-Temporal Coordinates

Extract

John said, “Sam went to the bank”. He meant it as a literal statement to be assessed as true or false. He meant by “bank” ‘financial institution', referring by it to the First National Bank of Muncie. By “Sam” he referred to Sam Jorgensen. Do we need to know any other sorts of facts about John's utterance to know how it is to be understood?

It might be argued that we do need to know something else, for suppose john produced an utterance fitting the above description before Sam went to the bank. Then what he said was false. If John produced an utterance fitting the same description after Sam went to the bank, then what he said was true. Whatever John says on any occasion, it surely can't be both true and false. But if what John said before Sam went to the bank equals what john said after Sam went to the bank, equals what john said, then what john said appears to be both true and false. The moral drawn by this argument is that on the two different occasions john said two different things. So full specifications of what John would have said on the two different occasions must be different. These specifications must, then, differ by features not yet mentioned.