Towards an Intensional Notion of Harmony

In this chapter we discuss how the intensional account of harmony sketched in the first chapter can be developed in a systematic way for a class of connectives whose rules are obtained in a uniform way using an inversion principle. To handle disjunction and disjunction-like connectives, the formulation of the expansions requires particular care. We discuss and compare two different ways of formulating the inversion principle and finally we investigate the prospects of developing an account of harmony for connectives whose rules do not obey inversion, pointing at the weakness of the approaches proposed in the literature so far.