Why the Universe Must Have a Cause
Claims that the universe is a mere brute fact violate the principle of sufficient reason
Can we say, “The universe simply exists, and that’s that—it has no explanation at all”? Some contemporary atheists seem to think so. Sean Carroll, a theoretical physicist at the California Institute of Technology, in a 2016 interview with Phil Torres at salon.com, says, “There’s certainly no reason to think that there was something that ‘caused’ it; the universe can just be.” Bertrand Russell, the late British atheistic philosopher, argued the same thing in a famous 1948 BBC radio debate with Fr. Frederick Copleston: “I should say that the universe is just there, and that’s all.”
Notice that neither Carroll nor Russell seems to be saying the universe is self-explanatory in that its existence belongs to its nature, which would be the sort of explanation for God’s existence. Nor do they seem to be saying that we don’t know what the explanation of the universe is.
Rather, it seems they’re saying there is no explanation for why the universe exists. In essence, they are denying the principle of sufficient reason, which states, “For everything that exists, there is a sufficient reason why it exists, either within itself or outside itself.”
Of course, this denial is detrimental to the project of reasoning to God’s existence, which depends on some things in our experience needing an external cause, whether it’s a cause that explains change or accounts for the very existence of things.
So, if something can exist as a brute fact, without needing an explanation either within itself or something outside itself (i.e., an external cause), then we’re blocked in our path to reason to God’s existence.
How should we respond? Are we to exchange brute fact for brute fact and say, “The existence of things just needs an explanation, and that’s that”? Or can we show the appeal to brute facts is unreasonable?
There are different ways we could argue against this brute-fact view (see sidebars). For the sake of this article, we’re going to focus only on one: defend the validity of the principle of sufficient reason (PSR) stated earlier.
Recall that the brute-fact view rests upon the denial of the PSR. If we can show that the PSR is a valid principle, then we will have shown that this brute-fact view is false and that there must be an explanation as to why the universe, or the things that make up the universe, have existence rather than not.
Our argument looks like this:
Premise One: If the PSR is true, then nothing, including the universe, can exist without a sufficient reason as to why it exists rather than not.
Premise Two: The PSR is true.
Conclusion: Therefore, nothing, including the universe, can exist without a sufficient reason as to why it exists rather than not.
Obviously, the main premise that we need to defend is premise two. So let’s do that! There are three arguments we can give.
No rational argumentation allowed
The first shows that to deny the PSR is to deny rational argumentation itself, including any argument for why a skeptic thinks the PSR is false. Let’s first think about what a rational argument entails. Consider this example:
Premise 1: All men are mortal.
Premise 2: Socrates is a man.
Conclusion: Therefore, Socrates is mortal.
We accept the conclusion as true because the premises are true, and the argument is logically valid. The premises and the logical structure of the argument serve as the reasons for our assent to the conclusion “Socrates is mortal.”
Now, if it’s possible that nothing whatsoever accounts for a thing’s existence, which the denial of our version of the PSR entails, then it would also be possible that nothing whatsoever accounts for the truth of our above conclusion.
Such a move is reasonable because no criterion is offered; nor can there be a criterion by which it’s possible to judge what is a brute fact and what is not. It would be arbitrary to say “brute facts” are allowed when we’re talking about the existence of things but not when we’re talking about conclusions in rational arguments. If brute facts are allowed in one domain, then they can be allowed in other domains.
But if it were possible that nothing whatsoever accounts for the truth of our conclusion “Socrates is mortal,” then our conclusion might not have anything to do with the premises and their logical structure, and thus we would have no reason to assent to its truth. It’s unreasonable to assent to a claim that might not have any connection to truth and logic.
This same line of reasoning can be applied to any conclusion that needs to be justified based on reasoning from prior premises, including the skeptic’s claim, “Things can exist without a sufficient reason for their existence.” Any prior premise on which a skeptic might base this conclusion could be dismissed, since on the brute-fact view the truth of prior premises might not have anything to do with the conclusion someone tries to deduce from them.
So, to deny the principle of sufficient reason as we’ve defined it is to undercut rational arguments themselves—including any argument a skeptic might give that the principle of sufficient reason is false. The denial of the principle of sufficient reason, therefore, is self-undermining. As such, we know it’s an invalid principle.
Undermining of reason itself
A second defense of the PSR goes even further and says that to deny the PSR is to undermine reason itself as a tool for knowing reality.
When we say something is true, we mean our judgment corresponds to reality—there’s something there in the outside world that matches what we’re saying in our minds.
For example, we say, “It’s true that the Statue of Liberty is made of copper.” Why do we say it’s true? Because that’s the way it is in reality. The Statue of Liberty really is made of copper. And it’s that reality that presses in on our minds, compelling us to make our judgment and serving as the reason why our judgment is true.
But, similar to what we said earlier, if it’s possible that nothing accounts for a thing’s existence, it would be possible that nothing accounts for the truth of our judgment that “the Statue of Liberty is made out of copper.” In other words, it’s possible that what’s out there in the real world is not the reason our judgment is true, since it’s possible there is no reason whatsoever why our judgment is true. And remember, since there’s no criterion for judging what’s a brute fact and what’s not, we’re justified in moving from the domain of the existence of things to the domain of the truth of our judgments.
Now, if it’s possible that the reality of things isn’t the reason why our intellectual judgments are true, then our reason is useless in knowing the real world. And if that’s the case, then all rational inquiry is useless, including science and philosophy.
Since that’s too high of a price to pay, we ought to accept as a valid principle the PSR as we’ve defined it here.
No contradictions allowed
Our third argument for defending the PSR shows that to deny the principle leads to a contradiction or the denial of a self-evident fact. And since we can’t accept either of those outcomes, we know the principle must be valid. There are two routes that we can take to show this.
Let’s start with Route 1: take a tree for example. When I look at the tree, I notice it exists—that’s to say, it’s a part of the community of real beings. And when I reflect a little more, I recognize that there must be something to the tree that distinguishes it from nothing. For if there were nothing to distinguish the tree from nothing, then the tree would be nothing. That “something” is existence (or being)—that by which a thing is actual. St. Thomas Aquinas calls it esse (the act of being).
Let’s suppose for argument’s sake that nothing whatsoever (neither the tree’s essence nor a cause) accounts for why the tree has existence rather than not, whether initially or presently. That would mean there’s no sufficient reason whatsoever for why the tree has existence rather than not, nothing in virtue of which the tree has existence.
In his book A Preface to Metaphysics, philosopher Jacques Maritain argues that to speak of that in virtue of which an object has existence (a sufficient reason for why a thing has existence) is the same thing as saying that without which an object doesn’t have existence.
So, to say there’s no reason as to why the tree has existence rather than not, neither within itself nor in some cause outside itself, is to say the tree lacks that without which it doesn’t have existence. But that just means the tree doesn’t exist.
A person who says there’s nothing to account for the tree having existence, neither its essence nor a cause outside itself, has two possible conclusions here. Either (a) he concludes that the tree doesn’t exist, or (b) he says the tree has existence and at the same time and in the same respect doesn’t have existence.
But neither conclusion works. Conclusion A doesn’t work, because it’s obvious the tree exists. Conclusion B doesn’t work either, because we can’t affirm a contradiction. Therefore, it can’t be that nothing accounts for why the tree has existence rather than not.
Here’s an example that may help to flesh this out.
Suppose we have a book that’s located above the ground on a shelf. And someone says that the book is above the ground in virtue of nothing—not the book itself nor the shelf. In other words, there’s no reason why the book is above the ground rather than not.
What would that entail?
Well, the book would lack that without which it wouldn’t be above the ground. But if the book didn’t have that without which it wouldn’t be above the ground, then the book wouldn’t be above the ground. So, for someone to say that the book is above the ground in virtue of nothing—not the book itself nor the shelf—is to say at the same time the book is not located above the ground.
Of course, this is a contradiction, which we can’t affirm. Nor can we say the book is not located above the ground, because that contradicts the fact that the book is located above the ground.
Therefore, we must conclude it can’t be such that the book is located above the ground in virtue of nothing whatsoever.
Similarly, we must conclude that it can’t be such that the tree has existence in virtue of nothing whatsoever, lest we say the tree has existence and doesn’t have existence at the same time or assert that the tree doesn’t have existence, which is contrary to the fact that the tree does exist.
The real is not nonreal
Let’s now look at Route 2 for showing that to deny the PSR leads to the affirmation of a contradiction or the denial of a self-evident fact.
Go back to the tree outside. When we look at it, we implicitly recognize that the tree exists, and the fact that it exists is not the same thing as it not existing. Implied in this is the judgment that existence (or being) is not nothing. Thomists capture this nicely in the phrase “Being is being and not nonbeing.” This is called the principle of identity.
Now, let’s take the brute-fact view and apply it to this distinction between being and nonbeing, or reality and nonreality, and see what we get.
The brute-fact view says it’s possible there’s no reason why something exists rather than not, which is just another way of saying nothing sufficiently distinguishes one state of affairs (the thing existing) from another (the thing not existing). If we apply that same reasoning to the distinction between being and nonbeing, it amounts to saying there’s nothing to sufficiently distinguish being from nonbeing, nothing to distinguish what’s real from what’s not real.
Now, if there were nothing to distinguish what’s real from what’s not real, then reality wouldn’t be sufficiently distinguished from nonreality. In other words, being would be indistinguishable from nonbeing.
But it can’t be that reality isn’t sufficiently distinguished from non-reality, because that would mean reality (being) is identical to nonreality (nonbeing), which is absurd.
Therefore, it can’t be that there’s nothing to sufficiently distinguish what’s real from what’s not real.
Let’s return to the tree.
We said a few moments ago that the tree has existence—that’s to say, it has that by which it is actual and a part of the community of real beings.
But that the tree has existence is itself a real state of affairs, a reality that’s distinct from nothing. Our judgment “The tree exists” corresponds to reality because the tree really does have existence.
Now, to say there’s no sufficient reason as to why this state of affairs (the tree having existence) is a reality rather than not (the tree not having existence)—or, to state it differently, nothing to sufficiently distinguish the real state of affairs that the tree has existence from the nonreal state of affairs that the tree doesn’t have existence—is to say there’s nothing to distinguish reality (being) from nonreality (nonbeing).
But, of course, if there were nothing to sufficiently distinguish the real from the nonreal, nothing to distinguish being from nonbeing, then the real would be identical to the nonreal. In the case with the tree, the real state of affairs that the tree has existence would be identical to the nonreal state of affairs that the tree doesn’t have existence.
So, to say there’s no sufficient reason for why the tree has existence rather than not is to either affirm a contradiction (the real state of affairs that the tree has existence is identical to the nonreal state of affairs that the tree doesn’t have existence), or to say the tree doesn’t have existence.
But neither conclusion works, since we can’t affirm a contradiction, and it’s obvious to our senses that the tree exists. Therefore, we must conclude it can’t be such that the tree exists without a sufficient reason, neither within itself nor in something outside itself.
It’s important to note that this same line of reasoning can apply to any and all beings that exist, including the universe. As such, it’s universally true that something can’t exist in virtue of nothing whatsoever. It applies to all things at all times and in all places.
Since the denial of the PSR, which we’ve called the brute-fact view, leads to the affirmation of a contradiction or the denial of a self-evident fact, we can affirm the validity of the PSR: for whatever exists, there is a sufficient reason why it exists, either within itself or in something outside itself.”
Sean Carroll is a brilliant man. Why such a great mind can’t see the rational implications of denying the PSR, I do not know. Perhaps he just hasn’t thought it through. Or perhaps he just isn’t willing to open the door to a line of reasoning that leads to theism. Whatever may be the case, the appeal to brute facts is not a good reason to close the door on theism.
Sidebar 1: Undermining Science
No atheist who thinks science is a legitimate enterprise for knowing reality should appeal to brute facts, because the brute-fact view entails radical skepticism about perception. As philosopher Alexander Pruss argues in several of his writings, if things can exist without any sufficient reason, then there might be no reason for our perceptional experiences.
For example, according to this line of reasoning, there might be no connection between your experience of reading this article and the actual article in the magazine. Your experience might just be a brute fact having nothing to do with any of the objective things with which we normally would associate your experience.
Do we want to go down that bleak road of skepticism and say all our sensory experiences are untrustworthy? There might be some radical skeptics who choose to walk that path (such skeptics can read this article). But for most reasonable people this is not a path that can be traveled, because such a path leads to the demise of science, which is something I assume people like Sean Carroll wouldn’t endorse because they would be out of a job.
We need to be able to trust our sensory perceptions if we intend to discover truths about reality through empirical observation. So, unless one is willing to throw science out, one shouldn’t allow brute facts into the game.
Sidebar 2: Double Standards
I find it interesting that an atheist is permitted to appeal to unintelligible brute facts, but the theist is not. If a theist were to say, “God is just a brute fact; there is no rhyme or reason to his existence,” then an atheist would feel justified in denying him membership in the intelligentsia.
This is manifest when atheists such as Richard Dawkins object to theistic arguments with, “Who designed the designer?”, thinking theists arbitrarily posit God as the terminus of causal series. If theists aren’t allowed to play the “brute fact” card (which we don’t do anyway), then atheists shouldn’t be allowed to do so, either.
Also, humans don’t appeal to brute facts when dealing with things in ordinary life. For example, suppose a team of police officers comes across a dead body on their shift and begin conjecturing possible explanations. “It’s murder,” one says. “No, I think it’s a suicide,” the other officer responds. Another officer says, “No, I think the cause of death was a heart attack.” The last officer says, “We’re wasting our time here. It’s just an unintelligible and inexplicable brute fact that this corpse is here. Let’s keep going.” What would we think of such a police officer? How about, “He’s not a good one!”
So, why should an appeal to a brute fact when faced with the existence of the universe be reasonable when an appeal to a brute fact when faced with a dead body is not?