Last November, we looked at what some call the existential argument for God’s existence. One of its key premises is that whatever doesn’t have existence by nature must receive its existence from a cause outside itself (an “existential cause”—a cause that gives existence). The argument then reasons that a series of such causes ordered in an essential way can’t regress infinitely, lest we deny the effect. And since this type of series can’t regress infinitely, we must conclude that there exists a first existential cause that is uncaused: what we call God.
There are several ways atheists might try and refute this argument. One is to challenge the premise that whatever doesn’t have existence by nature, such as a tree, must receive its existence from an outside cause. Perhaps the tree’s existence (or the universe’s), they argue, is just a brute fact. By cutting this link in the chain, atheists eliminate the need to trace the series of caused causes to a first cause, and thus the conclusion that God exists.
Does this parry the existential argument like atheists think it does? Let’s think it through.
Distinctions, distinctions, distinctions
We can start with the fact that the tree’s essence and existence are distinct. We know this is true because if the tree had existence by nature—that is to say, if it belonged to the tree’s essence to exist—then there never could be a time when the tree didn’t exist; just like there can never be a time when a triangle doesn’t have three straight sides, because three straight sides is identical to the essence of a triangle.
But obviously there was a time when the tree didn’t exist (it had to come into being from a seed or sapling), and there will be a time in the future when the tree will no longer exist (eventually it will die of old age, or be cut down, or burned). Therefore, the tree’s essence (what it is) is distinct from its existence (that it is).
Still with me? Okay, let’s move to the next step.
What’s on the table?
We know, however, that even though the tree’s essence and existence are different, they’re united: the tree exists. We have a unity of diverse principles.
Now, the unity of the tree’s essence and existence is going to be due either to the diverse principles themselves, or to nothing, or to some unifying cause outside the tree. Those are our only options on the table. Let’s take the first.
For argument’s sake, let’s say the tree’s essence is the reason for the unity it has with the tree’s existence—the reason why it exists. It would follow from this that the tree’s essence would have to include existence—for the tree’s essence couldn’t account for its existence if it didn’t have existence within it. But as we’ve shown above, existence doesn’t belong to the tree’s essence, since there was a time when the tree didn’t exist and will be a time when the tree doesn’t exist. Therefore, the tree’s essence can’t account for the unity it has with the tree’s existence.
Can the unity be explained by the tree’s existence? No.
To say that the tree’s existence is the reason for the unity it has with the tree’s essence is just another way of saying that the tree is that tree because it exists. In other words, by the sheer fact that the tree exists, it’s that tree. Yet a simpler way to put it: existence involves being that tree.
But if existence involves being that tree, then anything that exists would be that tree. You don’t have any leaves growing out of you, do you? I didn’t think so. Therefore, the tree’s existence can’t be the reason for the unity it has with the tree’s essence.
Stay with me, we’re almost there! Let’s move to our next option: nothing.
Nothing accounts for nothing
Why can’t the unity of essence and existence in the tree be due to nothing? Let’s suppose, once again for argument’s sake, that there is no cause for the unity of the tree’s essence and existence. In other words, there is nothing to account for their unity. Think about that for a second, and let it sink in.
Now consider that if nothing accounts for their unity, then there is nothing to distinguish their unity from non-unity. But if there is nothing to distinguish unity from non-unity, then there is no unity.
Here’s where an important philosophical principle comes into play: wherever there is no difference (nothing to distinguish one thing from another) there is real identity. For example, if I said there is nothing to distinguish Fido the dog from nonbeing, it’s pretty obvious that Fido would be identical to nonbeing, in which case he wouldn’t be a being at all—he would be nonexistent.
Back to our tree. If there were nothing uniting the tree’s essence and existence—nothing distinguishing them from not being united—the unity of the tree’s essence and existence would be identical to the non-unity of the tree’s essence and existence (just like our nonexistent Fido). But if the unity of these diverse principles is identical to their non-unity, then they’re not united. And if no unity, then no existence for the tree!
Formulating the argument
Let’s come back to the surface and summarize our argument:
Premise 1: The unity of the tree’s essence and existence is due either to the diverse principles themselves, or to nothing, or to some unifying cause outside the tree.
Premise 2: The unity of the tree’s essence and existence can’t be due to the diverse principles themselves.
Premise 3: The unity of the tree’s essence and existence can’t be due to nothing.
Conclusion: Therefore, the unity of the tree’s essence and existence must be due to a cause outside the tree.
This same line of reasoning applies to any being whose essence and existence are distinct. Therefore, we can say that whatever doesn’t have existence by its very nature (its essence) must receive its existence from a cause outside itself (an “existential cause”—a cause that gives existence). And then we’re off to the races of the series of caused causes, which must terminate in a first existential cause that is uncaused, namely, God.
So, if you think it through, the need for everything that doesn’t exist by nature to have a cause is one link of the chain to God that our atheist friend just can’t sever.
***This article was originally published by Catholic Answers Magazine Online on February 19, 2018.
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