We’ve going over the arguments for the existence of God using the book “Handbook of Apologetics” by Peter Kreeft and Ronald Tacelli. Kreeft teaches logic at a major university so his arguments are usually clear, concise and very helpful.
Two weeks ago we went over “The Argument From Efficient Causality” which brought up the following question: Why do we need and uncaused cause? Today Kreeft will answer the question “Why not have an endless series of caused causes into the past?”
So, here is the answer:
Question 2:
Why not have an endless series of caused causes stretching backward into the past? Then everything would be made actual and would actually be—even though their causes might no longer exist.
Reply: First, if the kalām argument (argument 6) is right, there could not exist an endless series of causes stretching backward into the past. But suppose that such a series could exist. The argument is not concerned about the past, and would work whether the past is finite or infinite. It is concerned with what exists right now.
Even as you read this, you are dependent on other things; you could not, right now, exist without them. Suppose there are seven such things. If these seven things did not exist, neither would you. Now suppose that all seven of them depend for their existence right now on still other things. Without these, the seven you now depend on would not exist—and neither would you.
Imagine that the entire universe consists of you and the seven things 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.
And if it must exist in that case, it must exist in this one. In our world there are surely more than seven things that need, right now, to be given being. But that need is not diminished by there being more than seven. 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.
Kreeft, P., & Tacelli, R. K. (1994). Handbook of Christian apologetics: hundreds of answers to crucial questions (pp. 52–53). Downers Grove, IL: InterVarsity Press.