Particularity and distrust of particularity is fundamental to the Enlightenment thought, at least for its mainstream strands. Utopian thought is so crucial for Enlightenment mainly because it transfers it beyond the particularity, beyond the present (which is by definition specific and particular).
Furthermore, freedom, especially negative conception of freedom, is the core concept of Enlightenment because freedom is nothing but the distrust of particularity.
The will to formality is a will not to be bound by any particularity.
Habermas, though thoroughly reconceptualizes the relation between particularity and generality in relation in positive terms, ultimately he still remains faithful to Enlightenment’s privileging of generality.
The role of a certain conception of generality and its relation to particularity and its bearing on the possibility of reflection is crucial to understanding Habermas’ conception of rationality. Strangely enough it remains an under-researched topic in Habermasiana. I am currently writing a short paper on the topic. Any suggestions, comments, collaborations are most welcome.