 Orthographic metaplasms have been used in philosophy to advance humanity's conceptual terrain, such as when Derrida adapted Heidegger's Destruktion into deconstruction or the French term "differénce" into différance.Changes at either level may or may not be recognized in standard spelling, depending on the orthographic traditions of the language in question.Originally the term referred to techniques used in Ancient Greek and Latin poetry, or processes in those languages' grammar.