After all of the underbrush of Between Facts and Norms is cleared - all the constitutional identity stuff, all the deliberative democracy stuff, etc - there's still the naive question: what, exactly is between facts and norms? This is obviously the space where facticity intersects with validity, but that's a trivial result based as much on synonyms as on analysis. Slightly less trivial - but still too abstract to be any good - is the observation that the space between facts and norms links the two together. In other words, that it provides the medium for communication between the two dynamics - that it binds them together by channeling something between the two of them. That something will turn out to be communicative power, but that's another post.

What we're interested in here is the way in which what is to be communicated comes about - specifically the debt that Habermas explicitly acknowledges he owes to Peirce on this issue. For Habermas, the space between facts and norms partakes of - but is not self-identical with - the lifeworld. It is, however, a social lifeworld self-reflexively constituted as outside the legal system, in a vulgar sense a more "social" reading of the lifeworld. This space is constituted by the background consensus of shared linguistic habits of communication - and by the implicit communicative assumptions that must also be shared for those linguistic habits to have formed. Into this space Habermas reads an essential fallibilism that he gets directly from Peirce.