Stephen Schiffer

S produces the sounds “It’s snowing” in the presence of A, and A instantaneously comes to know that it’s snowing. S has communicated to, or told, A that it’s snowing, and, as a result of S’s speech act, A came to know that it was snowing. Philosophical interest in communication turns on four inter-related questions. The first is about the logical structure of communication, or, more specifically, about whether communication is a relation that holds among three things just in case the first communicated the second to the third. The second is about the explication, or analysis, of communication. The third is about the role of communication in the explication of linguistic meaning. And the fourth is about how knowledge is acquired by communication. The questions are interrelated in that answers to any one question may constrain answers to one or more of the others.

SI is a paradox because it presents four appearances that cannot all be veridical: first, it appears to be valid—after all, it’s both classically and intuitionistically valid; second, its sorites premiss, (2), seems merely to state the obvious fact that in the sorites march from 2¢ to 5,000,000,000¢ there is no precise point that marks the cutoff between not being rich and being rich; third, premiss (1), which asserts that a person with only 2¢ isn’t rich, is surely true; and fourth, the conclusion (3), which asserts that a person with 5,000,000,000¢—i.e. $50 million—isn’t rich, is surely false.