Definition: That step forward in which one allows his reason to move along with the movement of the Truth in order to acquire the mode of rationality for apprehending the Truth that moves and lives and acts upon us in history.
More about the term: The Reformation opened up the historical perspective of understanding and initiated a historical mode of thinking, due as much as anything else to the Old Testament studies. However, the Reformation did not have the philosophical or intellectual tools with which to consolidate that insight and elaborate the change in method, and so Protestant theology soon fell back upon the old Aristotelian tools of thought. Consequently the development of historical thinking was severely retarded. When it did finally break out, however, it developed in two ways, each involving a fundamental error at the root, i.e. the historical thinking of the Enlightenment on the one hand and of Romanticism on the other hand. It is this duality that is ultimately responsible for the false problem in which the Dilthey-Troeltsch-Herrmann-Bultmann line of thought is entangled in their distinction between Historie and Geschichte.
The Lutheran philosopher, Søren Kierkegaard saw this task and question differently than his predecessors. Kierkegaard thought by ‘leap of faith.’ He was concerned about finding a mode of knowing appropriate to the nature of the Truth. The Truth with which we have to do in theology is the Being of God in space and time, the movement of the Eternal in our temporal existence, the Life of God in human history, in the concrete particularity of Jesus Christ. If the reason is to act rationally here, it must allow the nature of this Truth to prescribe for it the mode of thinking and the mode of demonstration appropriate to it. Because the Truth is the Eternal moving into time, the reason must move along with it in order to know it, and hence must make a break with other habits and structures of rationality which it had to develop in its knowledge of determinate objectivity in the world around.
*For more see this in Thomas F. Torrance’s Theology in Reconstruction (Eugene, OR: Wipf and Stock, 1996), 72-73.