The proper use of reason and philosophy in theological discourse rests upon recognition of their place and the limits of their competence. Truth, comments Turretin, cannot be set against truth–rather, one truth may transcend another. Thus truths of sense stand below truths of reason (infra rationem), truths of the intellect in immediate relation to truths of reason (juxta rationem), and truths of faith above those of reason (supra rationem). Once this pattern is recognized and the hierarchy of truth acknowledged, then rational truth can be used in theological discourse: “grace does not destroy nature but perfects it, nor does supernatural revelation abrogate the natural, but cleanses it.”
Richard A. Muller, Post-Reformation Reformed Dogmatics, vol. I, 387.