Opposition to extension or dissemination of knowledge beyond certain limits and to questioning dogmas. Obscurantism is the opposite of freethought and is often associated with religious fundamentalism by its opponents. Indeed, it is a commonly raised accusation in debates on academic freedom, with anti-communists and others associating it with the philosophy of G. W. F. Hegel and his followers (including Karl Marx) and more recently with opponents of Martin Heidegger doing the same.