ABSTRACT
This chapter explores the methodological impact of developments in the philosophy of mathematics on the formalisation of economics. It focuses, post-Keynesian economics and its emphasis on the role of conventions in economic decision-making in the face of radical uncertainty. The chapter shows how economic decision-making in the face of radical uncertainty is rational in a way which does not reduce its rationality to the orthodox characterisation of rationality. It also focuses on major developments in the philosophy of mathematics, viz. the emergence of the twentieth-century modal logic, Brouwerian intuitionism and the Church-Turing thesis. The chapter argues that extensional logic is the one and only true logic. It draws the reader's attention to the lack of consensus on this philosophical thesis of the reduction of the whole of logic to classical extensional logic. The chapter suggests that the resources of modal logic could prove fruitful.
