I understand that God is the First Cause of everything and that we are just secondary agents. We are secondary causes, no? Why?
Please respond only if you know the accepted teaching of theologians on this subject. Thank you so much, and God bless you.
To add to Linus2nd’s excellent answer, the basic idea is that God is the cause of the very
being (or existence, although that term is a bit misleading; see below) of His creatures.
His creatures (not just men, but also the angels and sub-human creatures), however, are also causes in their own right. They, however, are the causes not of other creatures’ very
being, but of what Thomas calls their coming-to-be (
fieri).
What is the difference? When we “create” something, we always take a pre-existing material and turn it into something else. This works across the board: when we create works of art or architecture, when a bird builds a nest, when an animal is conceived or dies, when there is a natural disaster, whatever it is: there is something pre-existing that is merely
transformed.
The only exception in our experience (apart from the exceptional case of the Sacrament of the Eucharist) is the generation of human life: when a human being is conceived, God creates his soul directly; it does not come from his parents. (And even that is not obvious: it takes some very subtle philosophical arguments to be able to see that.)
But these transformations that we witness raise an interesting question: where do these pre-existing beings come from in the first place?
It turns out that they would have no consistency whatsoever unless God created them and sustained them continuously in being. That is what it means to be the
primary cause. The rest of us, who merely effect
transformations, are secondary causes.
One of the things that we have to get our minds around when reading Thomas Aquinas is that he does not have the modern notion of “existence” at all. For us post-moderns (who still work with, or react against, the cultural heritage begun by René Descartes) “existence” is like a switch: it is either on or off, and there is no “gray” area in between. Some philosophers even equate “existence” with mere “appearance” (perhaps most famously Immanuel Kant). But not Thomas.
For St. Thomas, “being” (he hardly ever uses the term “existence”) is more like the light in a light bulb. It can be on or off, certainly, but it also admits of degrees of brightness. And even the image of the light bulb can be misleading: a light bulb, naturally, exists even when it is off. But a creature does not exist in any way (not even, strictly speaking, in the mind of God) until God has created it. Following this (very poor) image, God would be the pure light, so intense that it cannot be contained by any light bulb.
Another weakness of the light-bulb image is that light bulbs produce light on their own. In reality, God communicates His Being to His creatures. That is how He creates.
Perhaps a better image to evoke this second idea is the sun, and the moon and planets. The origin of all the light in the solar system (for all intents and purposes) is the sun. Some of the planets are more capable of capturing that light than others; they are, therefore, brighter than the others. But there is nothing as bright as the sun, and the sun is bright in a very different way: it produces the light. Moreover, if the sun were to be extinguished, all of the planets would be in impenetrable darkness.
Creation works something like that (with the caveat that even the planets function as a kind of pre-existing “substrate” that receives the light of the sun; God’s creatures, however, cannot exist independently from His Being in any way). They have differing abilities to receive being from their Creator. That is why some creatures are greater in stature than others: angels are (by nature) a superior kind of being to man; man is superior to the animals; animals superior to plants, and so on.
So anyway, you see the difference? God is the primary cause, because He communicates His Being. He has endowed his creatures with the ability to transform each other in various ways; that is secondary causality.
