Shearmur argues for the importance of Popper’s ideas about World 3, and against the idea that they should be re-interpreted in social terms. However, he also argues for the importance of Popper’s ideas about methodological rules—and that these may be given a partially social interpretation. The content of our ideas may in consequence differ from what we take it to be, as a consequence of our institutions and practices operating as methodological rules. He also explores related ideas about the interplay between World 3 and social factors in connection with Darnton’s ideas about the book and work that has built on it, and related issues about the public sphere and the problem of effective deliberative feedback on public policy.