possible for an inner process of the mind or soul to be brought into agreement with the things out there? And so begin the various attempts to explain it, all within an unclarified sphere.
If we consider that for a long time the essence of man has been experienced as animal rationale, i.e., as the thinking animal, then it follows that ratio is not just one power among others but is the basic power of man. That to which man is empowered by this power is decisive with regard to his relation to the verum and falsum. In order to obtain the true as what is right and correct, man must be assured and be certain of the correct use of his basic power. The essence of truth is determined on the basis of this assurance and certitude. The true becomes the assured and certain. The verum becomes the certum. The question of truth becomes the question of whether and how man can be certain and assured about the being he himself is as well as about the beings he himself is not.
The Roman world in the form of the ecclesiastical dogmatics of the Christian faith has contributed essentially to the consolidation of the essence of truth in the sense of rectitudo. The same realm of Christian faith introduces and prepares the new transformation of the essence of truth, the one of verum into certum. Luther raises the question of whether and how man can be certain and assured of eternal salvation, i.e., certain of "the truth." Luther asks how man could be a "true" Christian, i.e., a just man, a man fit for what is just, a justified man. The question of the Christian veritas becomes, in the sense just articulated, the question of iustitia and iustificatio. As a concept of medieval theology, iustitia is rectitudo rationis et voluntatis—correctness of reason and will. Rectitudo appetitus rationalis, the correctness of the will, the striving for correctness, is the basic form of the will in its willing. Iustificatio is already, according to medieval doctrine, the primus motus fidei—the basic stirring of the disposition of faith.1 The doctrine of justification, and indeed as the question of certainty of salvation, becomes the center of evangelical theology. The essence of truth in the modern period is determined on the basis of certainty, correctness, being just, justice.
The inception of the metaphysics of the modern age rests on the transformation of the essence of veritas into certitudo. The question of
1 Sancti Thumae Aquinatis Opera Omnia. VI. Commentum in Quatuor Libros Sententiarum. Volumen Primum. Distinct II, Quaest I. Art V. Expositio textus Justitia hic sumitur pro justitia generali, quae est rectitudo animae in comparatione ad Deum et ad proximum et unius potentiae ad aliam, et dicitur justitia fider, quia in justificatione primus motus est fidei ... [Exposition of the text here justice is taken as general justice, which is the correctness of the soul in comparison with God and neighbor, and of one power of the soul with the other, and it is called justice of faith because in justification occurs the first motion of faith. —Tr]