"For Habermas, the concept of unconditionality is primary, and this can in turn (if successful) ground his conception of context transcendence, in the sense of 'shooting' each and every context. I remain sceptical however that the idea of universality as agreement on the validity of claims, in the double sense of the term universal mentioned earlier, can be salvaged even by means of this strategy.
To understand this conception of unconditionality we need to recognise the key idealist premises and presuppositions that Habermas continues to cleave to even after the linguistic turn and detranscendentalisation. Habermas holds fast to the fundamental idealist premise that empirical order and rational order are mutually exclusive. Habermas' claims about the detranscendentalisation of the subject and reason, and his claim that reason is a 'thing of this world,' does not in any way mean that he has given up the fundamental idealist belief mentioned above. Rather what he does, in his own words, is to bring down the idealisation “from transcendental heaven to the earth of the lifeworld. The theory of communicative action detranscendentalizes the noumenal realm only to have the idealizing force of context transcending anticipation settle in the . . . heart of ordinary, everyday communicative practice.” (BFN: 19). Habermas does not aim to abolish the noumenal realm; so much as to bring it back to the earth."
Ali Rizvi, Validity claims, Unconditionality, Universality and Modernism in Habermas: A reappraisal, (forthcoming).