  Medieval theories of the transcendentals present an explication of the concept of ‘being’ (ens) in terms of the so-called ‘most common notions’ (communissima), such as ‘one’ (unum), ‘true’ (verum), and ‘good’ (bonum), and explain the inner relations and order between these concepts. In contrast to early modern accounts of the transcendental, these medieval theories regard the transcendental notions as properties of being and deal with the transcendentals within a conception of metaphysics as a ‘real science’ (scientia realis). The introduction of the doctrine of the transcendentals fundamentally transformed the medieval conception of metaphysics: it became the ‘common science’, the ‘transcendental science’, and ‘first philosophy’ in a new sense. Medieval theories of the transcendentals vary with regard to issues like the number and order of transcendental concepts and the systems of conceptual differentiation; the conceptual unity that is granted to them (analogy vs. univocity), and the way the transcendentals relate to the divine.