public deliberation depends. The modes of justification we use in our moral and political deliberations, and the we determine which claims of others are valid, are what matter most, and what determine whether we are being "rational". Hence the role that Habermas sees for communicative reason is formulating appropriate methods by which to conduct our moral and political discourse. This purely formal "division of labour" has been criticized by Nikolas Kompridis, who sees in it too strong a division between practical and aesthetic reasoning, an unjustifiably hard distinction between the "right" and the "good", and an unsupportable priority of validity to meaning. Post-metaphysical philosophy There are a number of specific trends that Habermas identifies as important to twentieth century philosophy, and to which he thinks his conception of communicative rationality contributes. To look at these trends is to give a clear outline of Habermas's understanding of communicative rationality. He labels all these trends as being post-metaphysical. These post-metaphysical philosophical movements have, among other things: called into question the substantive conceptions of rationality (e.g. "a rational person thinks this") and put forward procedural or formal conceptions instead (e.g. "a rational person thinks like this"); replaced foundationalism with fallibilism with regard to valid knowledge and how it may be achieved; cast doubt on the idea that reason should be conceived abstractly beyond history and the complexities of social life, and have contextualized or situated reason in actual historical practices; replaced a focus on individual structures of consciousness with a concern for pragmatic structures of language and action as part of the contextualization of reason; and given up philosophy's traditional fixation on theoretical truth and the representational functions of language, to the extent that they also recognize the moral and expressive functions of language as part of the contextualization of reason. Explanation Habermas' conception of communicative rationality moves along with these contemporary currents of philosophy. Concerning (1) it can be said that: Concerning (2), Habermas clearly and explicitly understands communicative rationality according to the terms of a reconstructive science. This means that the conception of communicative rationality is not a definitive rendering of what reason is, but rather a fallible claim. It can prescribe only formal specifications concerning what qualifies as reasonable, being open to revision in cause of experience and learning. On (3) and (4), Habermas's entire conceptual framework is based on his understanding of social interaction and communicative practices, and he