 Here, having two truth values would mean being both true and false, a glut, or what Asenjo calls (following Kant) an antinomy. Asenjo simply seems to assume without further ado that there are antinomies, and in Asenjo and Tamburino 1975 asserts that they are “useful logical entities”, especially for dealing with paradoxes in mathematical contexts. Born in Buenos Aires, Asenjo came to the University of Pittsburg in 1963 as a professor in the mathematics faculty, where he was in contact with logicians such as Belnap, Anderson, their student Dunn (who thanks Asenjo in his 1966 PhD thesis, that also toys with true contradictions), and nearby, Meyer. By the mid-1970s, Richard Routley (Sylvan), in collaboration with Meyer, was developing a ‘dialectical’ position that rebukes what they call “the consistency hypothesis” and accepts some statements as both true and false (Routley and Meyer 1976; Routley 1977, 1979). In 1979, Priest’s paper “The Logic of Paradox”, developed eventually into the book In Contradiction (1987/2006), presented what are now the most famous arguments for dialetheism. In the collaboration between Priest and Routley, the contemporary dialetheic program was launched. Much of Priest and Routley’s early joint work is summarised in Priest et al 1989 (also available as Priest and Routley 1983). More recent developments are canvassed below. 