 It certainly has lost none of its explosive revolutionary force as a radical program for philosophy (Creath 2009), and this is what has most divided commentators. Like most revolutionary ideas, it has encountered steadfast and vocal resistance. Most commentators have been concerned to limit the scope of the principle of tolerance, to dilute it or trivialize it, while the appreciative minority has mostly remained defensive. Much of the literature, therefore, is devoted to clarification and the correction of misunderstandings (e.g., Goldfarb &amp; Ricketts 1992; Ricketts 1994; Goldfarb 1995), rather than positive explorations of the principle of tolerance and its consequences (with a few exceptions: Carus 2017, Kitcher 2008, Creath 2009, Kutz, Mossakowski, and Lücke 2010, Justus 2012). Thus the remainder of this section will, after a brief exposition of the book’s contents, focus on these recent discussions and clarifications. Carnap’s principle of tolerance is discussed in more detail in section 1 of the supplement  Tolerance, Metaphysics, and Meta-Ontology,  and the Logical Syntax more generally in the supplement  Logical Syntax of Language.