2 Old Puzzles, New Evidence

The social world abounds in paradoxes. One of the most prominent (and mind-bending) is the Liar's Paradox, a puzzle created by self-reference or our ability to make statements that refer to themselves. If a person says “I am a liar,” we are forced to conclude that the sentence is both true and false: a liar that tells the truth is not a liar; but then he is deceiving us, which confirms he is a liar after all, which in turn means he is telling us the truth, and so on. This circularity creates a prison for the mind, challenging our most entrenched intuitions of what truth and knowledge mean. The paradox presents an epistemological problem that has attracted constant attention over the centuries and has stirred many controversies in the attempts to solve it (Sainsbury 2008). As unnerving as the puzzle might be, however, its persistence has not been futile: it has encouraged philosophers and mathematicians to develop formal languages that do not fall into the contradictions of everyday talk. These formal languages, in fact, offer the encoding rules that make our current communication technologies possible—they are the languages that allow our computers to speak in their logically flawless way.