Let's continue exploring natural theology - what we can understand about God from human reason alone - with the Argument from Contingency. We've built up from some foundational terms to several proofs for the existence of God. (And we'll have quite a few more coming!)
The argument from contingency is also called the "first cause argument". You may hear someone talk about an argument from movement or motion or the "first mover", an argument from the beginning of the universe, an argument from present existence, or from goodness or value. Whew...
Why so many "from's"? As with many things in philosophy, this is all St. Thomas
St. Thomas Aquinas wrote about "five ways" to prove the existence of God from natural reason. Four of these are ways of arguing from contingency. Before we look at them individually, though, we should ask:
What is "contingency"?
The dictionary defines contingent as "dependent for existence, occurrence, character, etc., on something not yet certain; conditional".
Fr. Hardon, in his Modern Catholic Dictionary, says that the category of contingent things includes "whatever can be or not be other than it is; that which need not exist."
A contingent thing doesn't have to be. It might just as well not exist. You and I need not be here. My desk or computer or the air I'm breathing might not be here. There's no reason it must be.
Another way I like to put it is that contingent things have a "because". I am alive because my mother gave birth to me. You're reading this blog because I wrote it some time earlier.
I'm going shopping tonight because I got paid, because I have a job, because I learned how to do that job, because I attended a college that offered that major, because...
The chain of contingency
"Now, wait!" you might say. "The air has to be there, or else you couldn't be there." Yes and no. The air doesn't have to be there, not necessarily. However, if the air wasn't here, I wouldn't be either. I'm dependent on the air being here, and the air is dependent on something (the existence of oxygen, hydrogen, etc.; the laws of physics; and so on). There is a chain of contingency here - A dependent on B, which is dependent on C, which is dependent on D, and so on.
Let's look at it another way:
I'm alive because my mother gave birth to me. She's alive because her mother gave birth to her. She lived because her mother gave birth to her. And so on. I'm contingent on Mom, who is contingent on her mom, who is contingent on her mom, and so on all the way back. We're links in a family chain.
All contingent things have at least one link--they're dependent on something (or more likely many somethings).
The beginning of the chain
A single train car moving along is pulled by the one in front of it. That one is pulled by the one in front of it. We know there has to be an engine somewhere, however, even if we can't see it. It might be one train car down or it might be one thousand cars down, but it's there somewhere, pulling the load. The cars aren't just moving on their own.
The bus gets to my stop from the one before it. It gets to that stop from the one before it. Somewhere back there, there's a bus depot. It may be one stop back or one thousand, but it's there. We know it has to be there somewhere and that the bus didn't just appear at my bus stop.
Each chain of events or objects has an origin. There is a reason why something is. Contingency arguments all follow this same general line of thinking -- that no number of contingent things explain themselves. A thousand train cars moving doesn't explain the movement anymore than one train car does. There still has to be an engine. Any contingency argument will aim to show that there must be an engine for that train, and that engine can only be God.
Where to go next
Next, we'll look at four specific examples of contingency arguments from St. Thomas Aquinas. (This is all his fault, after all. And - hey! - blame is another type of contingency.)
If you'd like to read more, Contingency is #7 in Dr. Kreeft's list of Twenty Arguments For The Existence of God. He also covers it in more depth in The First Cause Argument.
Fr. Barron talks about contingency in his commentary video on Scientism and God's Existence.
contingent. (n.d.). Dictionary.com Unabridged. Retrieved April 03, 2014, from Dictionary.com website: http://dictionary.reference.com/browse/contingent
Hardon, John. 1999. "Natural Theology". In The Modern Catholic Dictionary. Inter Mirifica