They applied the "Page 99 Test" to their new book, Seven Puzzles of Thought: And How to Solve Them: An Originalist Theory of Concepts, and reported the following:
Page 99 of Seven Puzzles contains an important claim: a rational person who fully grasps a concept may use it on distinct occasions, while thinking he is using different concepts each time. The example follows a case described by Kripke: Peter sees Paderewski at a musical performance and thinks that Paderewski is a talented pianist. He sees Paderewski at a political rally, believes it to be a different person called "Paderewski", and, having pessimistic general views about the musical talents of politicians, thinks that Paderewski lacks musical talent. Our view on p. 99 is that Peter thinks contradictory thoughts, though he may well be fully rational.Learn more about Seven Puzzles of Thought at the Oxford University Press website.
This emerges as part of an originalist theory of concepts, according to which concepts are individuated by their origins. This is claimed to solve several philosophical problems.