People who learned their evolutionary theory from the cartoonist Gary Larson will recall pictures of life emerging from the sea to colonise the land. This was a difficult transition and possibly the first life forms that made the journey were amphibious, capable of living on land and in the water. Eventually more developed forms of land-living animals were free from the need to be in or near the water and they could range far and wide, so massive numbers of new species could evolve to occupy the huge range of new ecological niches that were available.
In this story, the “sea” is an intellectual environment where the water consists of positivism, justificationism, essentialism, subjectivism, plus reductionism and determinism. On the land the intellectual environment consists of the Popperian turns and people who take the turns do not need to dedicate careers to confirmation theory and the problem of induction, they/we can engage with substantive scientific and practical problems in a critical and imaginative manner without having to wait for the philosophers to solve the problem of justified beliefs, overcome the paradox of the ravens, or find a way to attach p values to theories.
I see Philip Kitcher as an amphibian, still concerned with the justification of beliefs (in the water) but also moving forward with the social turn to consider the function of conventions and rules of the game in science, epistemology and politics. It will be interesting to see if he can continue to move in the direction of the evolutionary/objective approach/world 3 to knowledge.
I think his attempt to recruit economic theory to mesh with his epistemology will work better with a more “Austrian” approach to economics and less emphasis on justified beliefs on the epistemological side. That means picking up more of the Popperian turns to consolidate the transition to the “land”! It is a pity that we are short of critical rationalists to exploit and consolidate Popper’s pioneering work.