Habermas’ theory of rationality is broad in scope and he appears to develop it throughout TOCA, but be begins with a preliminary account grounded in some conceptual analysis.
What does it mean to say that persons behave “rationally” in a certain situation or that their expressions count as “rational”? Knowledge can be criticized as unreliable. The close relation between knowledge and rationality suggests that the rationality of an expression depends on the reliability of the knowledge embodied in it. (TOCA, 8 )
This is Habermas’ first stab: to tie the definition of rationality to the idea of knowledge “embodied” in an expression.
Consider two paradigmatic cases: an assertion with which A in a communicative attitude expresses a belief and a goal-directed intervention in the world with which B pursues a specific end. Both embody fallible knowledge; both are attempts that can go wrong. (TOCA, 8, emphasis mine)
I am initially skeptical of the free use of “embody”–it appears to be doing a lot of work for Habermas, and he refrains from defining it explicitly, and instead builds it by example only. My fear is that such an explanatory tool built out of ad hoc examples without an overarching principle will be this theory’s weakest link. But despite my reservations, let’s open up the term to the possibility of definition within our system.
(DFN-EXP-EMBODY-KNOWLEDGE-?) What does it mean for an expression to embody knowledge?
In both cases, the critic refers to the claims that the subjects necessarily attach to their expressions insofar as the latter are intended as assertions or goal-directed actions. This necessity is of a conceptual nature. For A does not make an assertion unless he makes a truth claim for the asserted proposition p and therewith indicates his conviction that his statement can, if necessary, be defended. And B does not perform a goal-directed action, that is, he does not want to accomplish an end by it unless he regards the action planned as promising and therewith indicates his conviction that, in the given circumstances, his choice of means can if necessary be explained.” (TOCA, 9)
There are a number of presuppositions in the passage that I would rather not take for granted, but there is one in particular which we have already explored reasons for doubting. It appears, at least on a first reading, that Habermas believes that all goal-directed actions are tied to linguistic claims and explanations. But we have already discussed here and here that the connection between know-how and language is a weak one. It might be possible, then, for there to be goal-directed action that is not tied to language at all.