The Next Swan: Frank Ramsey, Variable Hypotheticals, and the Bet on Induction

In his essay “Two Faces of Common Sense” (1972) Popper wrote ‘We are seekers for truth but we are not its possessors’. In the same essay, Popper argues ‘The quest for certainty, for a secure basis of knowledge, has to be abandoned.’Popper wanted to separate (un)certainty and truth and he believed that science should seek truth. Two quotes from Popper: ‘science has nothing to do with the quest for certainty or probability or reliability’ and ‘we too see science as the search for truth’.For Popper, truth is fully independent of the believer. I have always struggled with the concept of ‘truth’ as ‘independent of the believer’. Maybe Popper did not want to replace God with Truth, but to me it could appear that way.My interest in the philosophical ideas of Frank Ramsey (1903-1930) followed from listening to a podcast ‘A tale of truth’ by Simon Blackburn in 2023. Frank Ramsey’s redundancy theory of truth appealed to me. Popper himself once thought the correspondence theory of truth was dispensable, and noted in “Conjectures and Refutations” that Ramsey had suggested it might be empty altogether. If you adopt the redundancy theory of truth, science becomes managing uncertainty and assessing universal laws for reliability.Reading the philosophical ideas of Frank Ramsey also addressed another issue I was struggling with. In his essay “Conjectural Knowledge” (1972), Popper’s rejection of induction is total at the logical level, while at the same time Popper argued that this creates no clash with rationality, empiricism, or scientific practice. My view is that people do reason non-deductively. Inductive reasoning has traditionally been interpreted through a deductive lens: an argument that has a conclusion and supporting premises. This interpretation works very well for deduction, but I think it is incorrect for induction. The re-interpretation of induction by Frank Ramsey provided an ‘a-ha’ moment to me.Finally, the Cox-Jaynes theory is widely used in Bayesianism. The Cox-Jay