Peirce and metaphysical realism

Continuing this post, since Wilber uses Peirce in his semiotic exploration we might also consider how Habermas uses and criticizes Peirce in Postmetaphysical Thinking, Chapter 5. One of those criticisms is that Peirce wants to think of semiotics without recourse to an intersubjective relationship (91). Instead Peirce grounds semiotics in a metaphysical, Platonist frame (93). This is explained in detail in section IV starting on 108. We might see here why Wilber uses Peirce to validate his own metaphysical realism. Also see this previous post for more background.