A key conception in the philosophy of Hegel, that certifies the reality of categories. A category is a synthesis of two opposed abstractions (e.g. becoming is a synthesis of being and not-being) and in turn will be one member of a pair of opposites: the dialectical progress of history unites or sublates the pair under a yet higher category. The only absolutely concrete universal is reality as a whole: an all-embracing system of thought. British absolute idealists, such as Bosanquet and Bradley, supposed that if the concrete universal is substantial and real it ought to be identified with individual things.