Berkouwer, G. C. The Triumph of Grace in the Theology of Karl Barth. Translated by Harry R. Boer. Second ed. Grand Rapids, MI: William B. Eerdmans Publishing Company, 1956.
On basis of the analogia entis, natural theology posits an essential readiness, an openness for the knowledge of God as that knowledge is already present in natural man prior to and apart from the encounter with the gracious God. This man of the natural theology is the man who knows God without the miracle of grace, he is the rich man who can know God without standing in need of grace…In natural theology man denies his being completely closed to revelation…For this reason it must be rejected without mercy.Berkouwer goes on to argue that von Balthasar has erred in thinking that Barth changed his mind and came to essential although implicit acceptance of the analogia entis.
It is therefore plain that in his struggle against the analogia entis, Barth is not concerned about the problem of analogical concepts in general, as these played a role especially in the Middle Ages, but that his concern is with the analogia entis (of God and man) in connection with our knowledge of the truth, the gracious God. In distinction from this analogy, Barth points to the ‘experiencing’ of God’s grace which is founded in God’s readiness, and which can never be explained in terms of an already present readiness in man. (185).
Coincidently, one of my colleagues here at PTS - Keith Johnson - has recently completed a dissertation that was at one time entitled, "Rethinking Barth and Aquinas: The Analogia Entis and the Söhngen-Barth Exchange." Keep an eye out for its publication and, if possible, get a hold of a copy of the dissertation. It is well worth your time. If one wanted to track Keith down, he will assume a teaching position at my undergraduate alma mater (Wheaton College, IL) this Fall.