Arguments for the Existence of God: The Argument of Efficient Causality
We notice that some things cause other things to be (to begin to be, to continue to be, or both). For example, a man playing basketball will be dribbling, but if he stops dribbling, the ball does not continue to dribble on its own.
Every reader of this article is dependent on other things; you could not, right now, exist without them. Suppose there are five such things. If these five things did not exist, neither would you. Now suppose that all five of them depend for their existence right now on still other things. Without these, the five you now depend on would not exist—and neither would you. Imagine that the entire universe consists of you and the five sustaining you. If there is nothing besides that universe of changing, dependent things, then the universe—and you as part of it—could not be. For everything that is would right now need to be given being but there would be nothing capable of giving it. And yet you are and it is. So there must, in that case, exist something besides the universe of dependent things—something not dependent as they are. If we, as, most matter is, dependent on something, the universe, made up of matter, is dependent on something.
And if it must exist in that case, it must exist in this one. In our world there are surely more than five things that need, right now, to be given being. But that need is not diminished by there being more than five. As we imagine more and more of them—even an infinite number, if that were possible—we are simply expanding the set of beings that stand in need. And this need—for being, for existence—cannot be met from within the imagined set. But obviously, it has been met, since contingent beings exist. Therefore there is a source of being on which our material universe right now depends.
Thomas Aquinas formulated such an argument like this:
There is an efficient cause for everything; nothing can be the efficient cause of itself.
It is not possible to regress to infinity in efficient causes.
To take away the cause is to take away the effect.
If there be no first cause then there will be no others.
Therefore, a First Cause exists (and this is God).
NOTE: Thomas' Argument from Efficient Cause begins with the empirical observation of causal sequence in the world. Hence, this argument is an à posteriori argument, and the conclusion is not claimed to follow with certainty.
There are objections to this made by Bertrand Russell, a very smart man, that God must have a cause if this argument is to be sufficient. However, nothing in our existent universe is what God is. ie, Immaterial, All-powerful, All transcendent, etc. For example, matter in motion has a cause. An immaterial, transcendent being is the only possible cause for an existing matter. To better clarify, God cannot have a cause by His own definition.