On pages 182-3 of his Introduction to Christianity, Ratzinger says:

With the insight that, seen as substance, God is One but that there exists in him the phenomenon of dialogue, of differentiation, and of relationship through speech, the category of relatio gained a completely new significance for Christian thought.  To Aristotle, it was among the “accidents”, the chance circumstances of being, which are separate from substance, the sole sustaining form of the real.  The experience of the God who conducts a dialogue…exploded the ancient division of reality into substance, the real thing, and accidents, the merely circumstantial.  It now became clear that the dialogue, the relatio, stands beside the substance as an equally primordial form of being.

I want to say two things about this quotation:  first, that Ratzinger is way off on Aristotle; and second, that he is completely right about what he ultimately wants to say.  But first, let’s talk about Aristotle.

Question:  “Why is an elephant big, gray, and lumpy?”

Answer:  “Because if it were small, white, and round it would be an aspirin.”

Accidents, even according to Aristotle, can be bound up with the essence of a thing.  Porphyry, the pagan interpreter of Aristotle, distinguished between “accidents” and “properties”, by which he mean accidents that flowed from the essence.  For example, that a duck is waterproof is no chance circumstance:  it flows from its nature as a water bird.  This is very basic stuff in Aristotelian philosophy, so it is striking that Ratzinger should thing all accidents are “chance circumstance”.

That the Christian experience should explode the distinction between substance and accident is impossible on three counts.  First, the distinction itself, as Aristotle puts it, is an absolute dichotomy:  that which exists in another is accident while that which does not exist in another is substance.  “Is” versus “is not” is hard to explode.  Second, although the Church Fathers were on the whole not familiar with Aristotle and followed Plato instead, the one part of Aristotle’s work they all followed was his logic.  They knew his Categories and used it.  So it’s unlikely that a distinction fundamental to the whole work of the Categories would be exploded by their faith.  Third, the Church actually uses this distinction in her dogmatic definitions concerning the Eucharist, so we do not by any means want to explode it.

But there is something strange about relation.  Already in Aristotle, one gets the sense that he finds it strange, but Aquinas (possibly depending on some Arab?) brings clarity to the issue:  relation is strange because it adds no being to a thing.  For example, if I am taller than John, then the reality is that I have a certain size, and when we consider that size towards John then we see that I am bigger, but this relation of “bigger” is not some other being in me besides my size.  Aquinas offers a beautiful and intellectually exhilarating account of how relation works out in the Trinity:  of all the categories besides substance, he says, relation is the only one that we could speak of in the Trinity precisely because it is the only one that does not add some extra being and so would not compromise the simplicity of God.  When Ratzinger says that Christians have found that relation “stands beside the substance as an equally primordial form of being”, he says the exact opposite of the truth.

And for all this, I think that Ratzinger is right.  To be sure, he has misunderstood Aristotle and the Aristotelians in a fundamental way:  when they say “substance”, he thinks they mean something inert that stands under accidents the way a pin cushion stands under the pins pushed into it.  He would rather that God, that Being, be something dynamic and active, something that strains forward to a goal, something that loves and burns.  And what he wants, I think, is in fact what good thomists mean by substance.

Substance is not something inert.  Natural substances bubble with activity, flow from origins, and yearn towards goals.  In fact, the very being of a man is the kind of being that must be from the first principle of being, and it is the kind of being that must strain forward to reach the end of all things.  By my being itself, and not by something added over and above my being, I relate to God as his creature and move toward God as my end.  A man who was not a creature and did not pursue his end would be a contradiction.

Ratzinger really brings out the fruit of his insight when he gets to Christology–amazing, amazing stuff.  In the meantime, I am convinced that he learned of Aristotle only through dry, stale manuals and that, despite his teachers, he saw his way through to the truth.