Eckhart does not signify one and the same reality by the names 'ground of the soul' and 'sparkle of reason'. Whereas the ground is the soul's essence, that is, the principle from which all the soul's powers flow, the sparkle is the natural knowledge belonging to one of these powers, namely to reason. Both Eckhart and Aquinas call reason's natural knowledge of good and evil 'synderesis'. The comparison between these two medieval theologians shows many convergences: they understand the natural cognition of the transcendentals, especially of being, as source of all knowledge. Inasmuch as being is the first principle of understanding, it provides intelligibility for the intellect. The understanding of being is a participation in God's cognition. Further, both Eckhart and Aquinas describe the soul's essence as form of the body, though it transcends the body insofar as it is intellectual. In this sense, the soul has a ground beyond her life-giving function regarding the body. Though we know, that this ground is, we cannot know what it is. Whereas the understanding of the sparkle is the foundation of any other cognition, the ground is something unknown.
