 Nietzsche’s unpublished writings often reveal his more tentative and speculative ideas. This material is surrounded by controversy, since some of it conflicts with views he expresses in his published works. Disagreement regarding Nietzsche’s notebooks, also known as his Nachlass, centers around the degree of interpretive priority which ought to be given to the unpublished versus the published writings. One popular approach in the tradition of classical scholarly interpretation is to maintain that Nietzsche’s published works express his more considered and polished views, and that these should take precedence over the unpublished manuscripts when conflicts arise; a second attitude, given voice by Martin Heidegger (who lectured on Nietzsche in Nazi Germany, 1936–1940), and broadly consistent with a psychoanalytic approach as well, is to regard what Nietzsche published as representative of what he decided was publicly presentable, and what he kept privately to himself in unpublished form as containing his more authentic views; a third, more comprehensive, interpretive style tries to grasp all of Nietzsche’s texts together in an effort to form the most coherent interpretation of Nietzsche’s thought, judging the priority of published versus unpublished works on a thematic, or case-by-case basis; a fourth position influenced by the French deconstructionist perspective maintains that any rigid prioritizing between published and private works is impossible, since all of the texts embody a comparable multidimensionality of meaning.