In an episode that may (or may not) be his magnum opus, Bruce introduces his term for Karl Popper’s idea that you are only allowed to solve problems with your (scientific) theory by making it more empirical, not less empirical.

Bruce makes the case that this is one of Karl Popper’s least appreciated ideas, as all of us are tempted by ad hoc saves that move our ideas in the direction of vagueness.

Bruce also considers where conjectures come from and if Popper thought there existed a scientific method.