Pragmatism is a method. It begins with a rejection of the Cartesian method and its dualism while sincerely reforming British empiricism. Pragmatists attempt to break out of the closed dialectics of rationalist and empiricist philosophies.
For Peirce, Pragmatism is a method of clarifying the meaning of highly difficult concepts and terms, including a critique of the ways in which we structure our inquiries. Peirce critically attacks the methods of Descartes.
William James asserts that Pragmatism is a theory of truth (as opposed to Peirce's theory of meaning) focused on the richness and abundance of experience. James is the American philosopher most responsible for amending empiricism to a radical empiricism. James accepts most of what Peirce says about pragmatism, but his method is more personal and custom-made with the intimacy of oneself.
John Dewey continues in this vein by critiquing modernity and its reliance on dualisms inherited through the Cartesian tradition. Pragmatism for Dewey is an instrumentalism, which views truth as "warranted assertion" following from our inquiries, which is a stabilization of our precarious situations.