By the 12th Century Christian philosophy was almost a thousand years old; the Christians had almost as much philosophy behind them as did the Greeks at the time of Plotinus. Whether all that thinking had helped them understand the murky parables of a certain Jewish carpenter was a difficult matter. But some things were getting clear in Paris.
Two mysterious 12th-century composers attached to the cathedral of Notre-Dame, Léonin and Pérotin, were introducing what amounted to harmony into Gregorian chant. The idea that voices singing different notes could be pleasing to God was to have enormous consequences, not least (I submit) on the philosophy of Thomas Aquinas, who arrived in Paris from southern Italy in 1245.
Reading Aquinas is a chore second only, in its mind-numbing difficulty and its endless length, to what must have been the job of writing him. The format is unvarying: he lines up authorities on both side of a question, states reasons for their positions, then identifies his own view and his reasons for it, refuting those authorities who disagree with him. A small conceptual shift then produces the next question, and the process is repeated. The questions follow each other, creeping in their petty pace from hour to hour unto the last syllable…of recorded truth.
But as they do, as you work along all this, a vision begins painfully to emerge. In particular, Aquinas’ technical and tortured discussions of the actus essendi, the act of being, attempt to explain what Aristotle could not: how essence comes to inhere in matter. Plato required that a form be the same for everything that “participated” in it: justice is always justice, wherever it is found.
It is thus a crucial aspect of the relation of participation that many things can participate in one form; but since Plato never clarifies the nature of participation (#8), we don’t know how that is supposed to work. When Aristotle converts form into essence by placing it within things, he agrees with Plato that all humans have exactly the same essence, humanity. But if that essence is one, how can humans be many?
For Aristotle, the answer is matter. That a single essence must bound, organize and control the differing matters of different beings means that the form’s activity itself modulates according to the matter in which that essence is, and the result is different individuals sharing the same essence. One essence acts in different ways at different places and times. Not very clear, but at least it’s an explanation.
But if essence “dominates” matter, then matter must, as we saw (#8), “resist” essence. It is the varying resistances offered by matter in differing times and places that modulate the activity of the single essence which controls them and so enables the one to become many. Such is the case for Aristotle, at least; but for Aquinas, essence comes from God. Resistance to God is sin, and only conscious beings can sin.
So Aquinean matter is inert, and cannot resist essence. Which leaves essence, so to speak, with nothing to do. Let me put it this way: for Aristotle, essence is in matter because essence is active, and its activity is to dominate matter. For Aquinas, essence is more passive: it does not dominate matter because matter does not resist it. So something else must “place” essence in matter.
Who is that something else? You know who. It is God Who places an essence in a number of bodies by constituting an actus essendi, an act of being—a notion for which Aristotle had no use. Because it pluralizes form, the actus essendi is not common to a number of things, as is the essence it posits in those things. Each act of being is unique.
The details escape me; let them go. The upshot is that the universe consists of an enormous number of beings, each unique at its core and each beloved of the God Who made it, and Whom it honors, just by being itself.
And the whole of reality, we might say, is like a giant choir in which each being sings its single note to God Himself, in an infinite polyphony.
This is surely one of the most powerfully beautiful ontologies ever formulated. And if it bears any truth at all, we moderns are in very serious trouble. For since we are not God, our manifold and growing interventions into the world God made are not improvements on His work. We are merely converting the divine polyphony into a cacophony which is, if human at the outset, virtually diabolical at its end. Every forest we cut down, every meadow we pave, every river we dam, and every lake we pollute becomes an insult to the God Who made them all.
Human interventions into nature must therefore be limited to those which enable us to be as God intended us to be—to those that enable us to be what we really are.
But who are we, really?