In the context of recent encounters on the question of free will and naturalism, Habermas has been described as compatibilist by some while incompatibilist by others. Abstracting from the debates on free will there is one issue on which Habermas is clearly an incompatibilist and that is the issue of the co-existence of what Sellars calls the “space of reasons” and the “space of law.” Habermas believes that the “space of reason” and “the space of law” are mutually exclusive. In this particular belief Habermas is a thorough going Kantian. However, if the story ended here it would not have been very interesting. What makes the story interesting is the way Habermas defends the Kantian incompatibilism about the “space of reason” and the “space of law.” Habermas aims to defend the Kantian incompatibilism about the two spaces without referring back to what Habermas takes to be the otherworldly realm of intelligible in Kant. In this paper I aim to show how Habermas defends the Kantian incompatibilism about the two spaces in wholly this-worldly terms without referring back to the Kantian realm of intelligible. Concentrating on Habermas’ concept of “communicative action” I construct a Habermasian argument for showing how the space of reasons emerges within this- worldly practices of communication without referring to any otherworldly entities. I understand the conditions of the creation of a space of reasons in terms of the conditions of the possibility of communicative action. I discuss in relative detail these conditions and relate them to the possibility of creating and sustaining the space of reasons without falling back on any otherworldly realms. In the concluding section I argue that although Habermas is successful in showing a way to maintain incompatibilism about the two spaces, his account is in danger of being engulfed by linguistic idealism of which he accuses Heidegger. It is in response to this danger, I argue, that Habermas has recently turned towards what he, following Putnam, sometimes calls “internal realism.” One of the functions of the proposed internal realism and weak naturalism is to ward off the suspicion of the aforementioned idealism. Although I would not be able to discuss this recent turn in this paper, I briefly describe how this turn gels with Habermas’ account of the incompatibilism of the two spaces offered in this paper. I also briefly describe the challenges faced by any such account.
(I am in the process of writing the above paper, any comments welcome)