Alright, I confess: I like Karl Rahner. He is difficult to read, even exasperating at times. I can only take him in small doses, but he makes me think even though I often find myself at variance with him. The way I see it he's worth the effort if only for the fact that he is perhaps the most important Roman theologian of the 20th century.
In particular I am attracted to Rahner's concept of human transcendence and how this relates to the Incarnation. But recently, in light of the discussions on this blog, I decided to review what he had to say about the Trinity in his monumental Foundations of Christian Faith (English translation, 1978). While I can't say that I was totally surprised to find elements of modalism in his understanding of the Trinity (after all, he is cut out of the same western Augustinian cloth), I will admit that I was shocked to see how blatent his modalism was. The following is an example of what I mean. What do you think?
Insofar as he has come as the salvation which divinizes us in the innermost center of the existence of the individual person, we call him really and truly "Holy Spirit" or "Holy Ghost." Insofar as in the concrete historicity of our existence one and the same God strictly as himself is present for us in Jesus Christ, and in himself, not in a representation, we call him "Logos" or the Son in an absolute sense. Insofar as this very God, who comes to us as Spirit and Logos, is and always remains the ineffable and holy mystery, the incomprensible ground and origin of his coming in the Son and in the Spirit, we call him the one God, the Father. Insofar as in the Spirit, in the Logos-Son, and in the Father we are dealing with a God who gives himself in the strictest sense, and not something else, not something different from himself, we must say in the strictest sense and equally of the Spirit, of the Logos-Son and of the Father that they are one and the same God in the unlimited fullness of the one Godhead and in possession of one and the same divine essence.
--Foundations of Christian Faith, p. 136.