Karl Rahner, in his famous work Geist in Welt (1939), tries to establish, from his Metaphysics of Knowledge (Erkenntnismetaphysik), the metaphysical foundations of the Freedom of the Spirit (Freiheit des Geistes). According to Rahner, appealing to Saint Thomas Aquinas, the metaphysical root of freedom lies in the independence of the spirit (consciousness) from sensitive matter, because of its anticipated orientation (Vorgriff) towards being in general (Sein überhaupt).
Although Rahner presents himself as a thomist, his metaphysics of knowledge, of a transcendental background, is inspired above all in Heidegger and Maréchal, rather than Thomas Aquinas. This infidelity to the Angelic Doctor is especially demonstrated in the question of being: in fact the being is understood as an indefinable, indefinite and empty concept. He conceives man as spirit, inasmuch as he is opened in advance to the being in general; he identifies being, knowing and the known; and finally he makes an unjustified saltus of the transcendental to the transcendent, falling into pantheism.