 While the word ‘dialetheism’ is relatively new, the idea is not. In this section we note some points in the history of philosophy where true contradictions appear salient, either explicitly or implicitly. (Much of this scholarship is due originally to Priest and Routley 1983, and Priest 1995/2002.) Then we address methodological issues to do with historical interpretation, and give a quick sketch of more recent history. For another history of dialetheism, see Ficara 2021. (Note that Ficara, following d’Agostini’s interpretation of Hegel, takes dialetheism to be the view that there are non-explosive true contradictions, and distinguishes this from glut theory, the view that there can be true and false propositions. This diverges from the way we’ve set things out here, and merits further discussion in itself.)