Gottfried Leibniz famously asked the question, “Why is there something rather than nothing?”  Leibniz was asking why does the universe exist rather than nothing at all? From this question Leibniz developed a simple but powerful argument for the existence of God. In this post I will introduce you to his argument and how answering his simple question gives us reason to believe that God exists.
In order to understand Leibniz’s reasoning there are three concepts we need to think through. These are Contingency, Necessity, and the Principle of Sufficient Reason.
Most of the objects that we can think of exist contingently. This means that their existence is contingent on factors outside of themselves. Think of a chair that owes its existence to the woodworker. If not for the woodworker, the chair would not exist. In this way the chair exists contingently because its existence is contingent on the woodworker.
The opposite of contingent existence is necessary existence. In this case the object does not owe its existence to anything but itself. Its existence is self-explanatory, rather than “other-explanatory”. Some mathematicians believe that numbers exist in this way. So if the number “7” is an actual thing that exists, there wouldn’t be anything that causes it to exist. In this way the number “7” would be a necessary object. William Lane Craig puts it this way, “According to [Leibniz] there are two kinds of being: necessary beings, which exist of their own nature and so have no external cause of their existence, and contingent beings, whose existence is accounted for by causal factors outside themselves.” 
The other concept that Leibniz’s argument uses is the Principle of Sufficient Reason. This is a logical principle that says for everything that exists, there is some sufficient reason or explanation for its existence. Nothing just exists without a reason. If you are a parent and you come home to find a smashed vase in your living room, then you automatically assume that one of your children has broken the vase. The inference to some explanation for its being broken is automatic and obvious. If your child said, “I don’t know, it just happened,” you would demand a better answer because you know better. Douglas Groothuis explains the principle this way, “For everything that exists, there is a reason for its existence, either due to the causal efficacy of other beings [contingency] or due to the necessity of its own nature.” 
So how do we get to God?
Leibniz took these concepts of “necessity” and “contingency” and asked the question, what sort of existence does the universe have? What is the explanation for why the universe as a whole exists? It seems that if the universe does not exist by necessity, then it must exist contingently, and if the universe is contingent on anything then that thing must be God.
The reason why the explanation for the universe must be God is found when we consider what is being explained. When we refer to the universe, we are talking about all of space, time, matter, and energy. Whatever stands as the explanation for these things must transcend them. For example, if the foundation for matter was itself material, then you would have to first have matter before you could explain the existence of matter. But this would be like saying that you have to have sunlight before you could have a sun, which is absurd. So the explanation for time, space, matter, and energy must be timeless, spaceless, and immaterial.
In addition to these attributes, the transcendent explanation must be uncaused and personal. Since to be caused is to be explained by another, a necessary being must be uncaused. If the transcendent explanation were caused then it would itself be contingent and there would be yet another explanation above it. So whatever stands as the necessary being that explains the existence of everything must be uncaused.
It must also be personal, and Craig explains why, “The cause of the universe must (at least causally prior to the universe’s existence) transcend space and time and therefore cannot be physical or material. But there are only two kinds of things that could fall under such a description: either an abstract object (like a number) or else a mind (a soul, a self).”  Numbers do not cause anything (the number “5” never put $5 in my pocket), and so by process of elimination the cause of the universe must be a mind or soul.
So we see that Leibniz’s argument is subtle but powerful. As Craig goes on to explain, “I hope you begin to grasp the power of Leibniz’s argument. If successful, it proves the existence of a necessary, uncaused, timeless, spaceless, immaterial, personal Creator of the universe.” 
What if the universe caused itself?
If something has the potential to come into being then that potential must be actualized by something outside of itself. The universe undeniably had the potential to exist, but something outside of itself had to realize that potential. Norman Geisler explains, “no potentiality can actualize itself, any more than the potential for steel to become a skyscraper can actualize itself into a skyscraper.”  For this reason the mere potential for there to be a universe is not enough to explain why there is a universe.
At this point some might argue that since the universe is not an object but a system of objects that the explanation can ultimately be found within the system. In the case of each object its explanation is found in another object, but through the system of objects everything is ultimately explained. This won’t work either, and Geisler explains why, “To say it could is like arguing that one paratrooper whose chute did not open can hold up another whose chute did not open. And adding more paratroopers whose chutes do not open does not help the problem; it compounds it.”  In other words, we must have an ultimate explanation that is self-explained (necessary). We need a paratrooper whose chute is open and who does not rely on any other paratroopers to hold him up. With a universe of contingent objects, there must be a necessary object to ground them.
So why can’t the universe be the necessary object? There are at least two reasons that the universe cannot be a necessary being. First, the scientific consensus is that individual subatomic particles in the universe are not necessary beings. These subatomic particles could have been different or could have failed to exist. Since the universe is just a collection of these particles, the universe itself could also have been different or failed to exist. As Craig puts it, “No one thinks that every particle in the universe exists by a necessity of its own nature. It follows that neither does the universe composed of such particles exist by a necessity of its own nature.” 
Some might push back and accuse the argument of the Composition Fallacy at this point, but this move would be wrongheaded. The Composition Fallacy points out that a collection of things does not necessarily possess all of the attributes of the individual objects. So a brick wall is heavy even though individual bricks are light. The critic might say that the objects within the universe are contingent but the universe as a whole may not be contingent. Someone would be committing the Composition Fallacy to say otherwise, according to the critic.
When it comes to the composition fallacy, however, it is the “accidental” qualities of the object that may not translate rather than the “essential” qualities. Accidental qualities are those qualities that an item happens to possess given the circumstances. So a brick happens to be light because it has been cut small. You could cut a brick the size of a house and it would be heavy instead. So its weight is an “accidental” quality because it is not the essence or nature of brick to be any particular weight. An essential quality of brick might be that it occupies space. If we strip away this quality, then whatever we are discussing is no longer a brick at all but something else entirely. No matter how many bricks you might add, you will never reach a point that they no longer occupy space. When it comes to the universe, no matter how many objects that are by nature contingent that you add, you never get to a universe that is necessary.
The most obvious knockdown argument against the universe existing by necessity, however, is the beginning of the universe. If something has to exist so that it is impossible that it could have ever failed to exist, then it can never have come into existence. As Craig explains, “An essential property of a being that exists by a necessity of its own nature is that it be eternal, that is to say, without beginning or end. If the universe is not eternal, then it could fail to exist and so does not exist by a necessity of its own nature.” 
When we answer Leibniz’s original question, “Why does something exist rather than nothing?” we are ultimately drawn to a being that must exist by the necessity of its own nature. When we look out and see a world full of contingent objects and we consider what explains their existence we must eventually come to an explanatory stopping point. We inevitably come to a self-explained explainer of everything that exists. This being is timeless, spaceless, immaterial, personal, and is the foundation for all reality. It is what we are referring to when we use the word “God”, and Leibniz’s argument gives us good reason to believe that he exists.
If you found this post helpful, please click the “Follow” button at the bottom of the page to sign up for new posts as they come out. Below is a brief video produced by ReasonableFaith.org that further explains Leibniz’s argument.
 Douglas Groothuis, Christian Apologetics: A Comprehensive Case for Biblical Faith – Kindle (Downers Grove: InterVarsity Press, 2011), Ch 11, paragraph 2.
 William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton: Crossway Books, 2008), pg 107.
 Douglas Groothuis, Christian Apologetics: A Comprehensive Case for Biblical Faith – Kindle (Downers Grove: InterVarsity Press, 2011), Ch 11, The Principle of Sufficient Reason and the Existence of God.
 William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton: Crossway Books, 2008), pg 108.
 William Lane Craig, On Guard: Defending Your Faith With Reason and Precision – Kindle (Colorado Springs: David C. Cook, 2010), Ch 3, Another Argument for Premise 2: The Cause of the Universe: Abstract Object or Unembodied Mind?.
 Norman Geisler, Systematic Theology in One Volume (Bloomington: Bethany House Publishing, 2011), pg 24.
 ibid, pg 25.
 William Lane Craig, On Guard: Defending Your Faith With Reason and Precision – Kindle (Colorado Springs: David C. Cook, 2010), Ch 3, Atheist Alternative: The Universe Exists Necessarily!.
 William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton: Crossway Books, 2008), pg 111.
Image Attributions (by order of appearance):
- Featured Image: Artem Ball on unsplash.com
- Fachdozent at pixabay.com
- tanakawho at Flickr: Creative Commons
- Juskteez Vu at unsplash.com
- Fairygoat at Flickr: Creative Commons
- anonymous at pexels.com
- katarzyna at Flickr: Creative Commons