Philosophies may be exact or rigorous to different degrees, from the ones cast in mathematical terms to those that openly spurn rigor. Among the latter are the doctrines that place feeling or intuition over reason (like Rousseau"s, Vico"s, and Bergson"s), exalt everyday language (like Wittgenstein"s), praise "weak thought" (like Gianni Vattimo"s), attempt to pass off obscurity as depth (like Hegel"s and Husserl"s), love the absurd (like Heidegger"s and the postmodernists), or tell us solemnly that matter and mind are eternal mysteries (like the later Chomsky"s).