“The doctrine of the Trinity is only possible as a piece of baffled theology,” writes Joseph Ratzinger (Introduction to Christianity, 122).
This is true in a sheer historical sense: “Every one of the big basic concepts in the doctrine of the Trinity was condemned at one time or another; they were all adopted only after the frustration of a condemnation; they are accepted only inasmuch as they are at the same time branded as unusuable and admitted simply as poor stammering utterances” (122).
“Person” (prosopon) was condemned. So was homoousios, and so was “proceed.”
Ratzinger doesn’t see these condemnations as mere errors. They become integral to the “later formulas of faith.” The heresies thrown up on the way to the dogma of the Trinity aren’t merely gravestones, but are ciphers that represent “an abiding truth, a cipher which we must now preserve with other simultaneously valid statements, separated from which it produces a false impression” (123).
He turns to modern physics to grasp the logic: “The physicist is becoming increasingly aware today that we cannot embrace given realities – the structure of light, for example, or matter as a whole – in one form of experiment and so in one form of statement; that on the contrary from different sides we glimpse different aspects, which cannot be traced back to each other. We have to take the two together . . . without being able to find any all-embracing aspect” (123).
He is even willing to speculate that, as physicists have speculated, there may be beings that have no substance but are “purely actual, whose apparent ‘substantiality’ really results only from the pattern of movement of superimposed waves.” He knows that it’s a controversial point, but is excited by the hint that “for the actualitas divina, for the absolute ‘being-act’ of God, and for the idea that the densest being – God – can subsist only in a multitude of relations, which are not substances but simple ‘waves,’ and therein form a perfect unity and also the fullness of being” (124-5).