A SUMMARY OF FODORIAN THESIS o The thesis of modest modularity as i shall call it has two strands. The first strand of the thesis is positive. It says that input systems, such as systems involved in perception and language are modular. The second strand is negative. It says that central systems, such as systems involved in belief fixation and practical reasoning, are not modularA SUMMARY OF FODORIAN THESIS  The thesis of modest modularity, as I shall call it, has two strands. The first strand of the thesis is positive. It says that input systems, such as systems involved in perception and language, are modular. The second strand is negative. It says that central systems, such as systems involved in belief fixation and practical reasoning, are not modular