Clarifying Arguments for God, Part One: Cosmological

There are many good arguments for the existence of God, each with their own strengths and difficulties. As some arguments have become more popular, however, certain confusions have entered into the mix even among Catholics and other Christians, and have weakened the case for God even among those who want to know and defend the truth.

This can have negative consequences for Christian apologetics, because when arguments are misunderstood they can be easily dismissed. And it is important that we do not assume that because one has had an education in the Faith, that they are prepared for every challenge.

For example, some years ago the daughter of a popular Christian apologist lost her faith when she found herself unable to answer a theological question. As was clear from her own account, the question itself contained some confusion about natural law and God’s covenant commandments, but she did not recognize the error. One must wonder what would have happened if she had been more aware of the distinctions that would have allowed her to confidently answer the challenge.

This is the first article in a three-part series, in which we will clear up some of these confusions.

Cosmological arguments proceed from the existence of the cosmos to its creator. The basic idea is that all effects require a cause, and a key ingredient in many such arguments is that an “infinite regress” (an actual infinite quantity) cannot be used to multiply causes and avoid an ultimate cause (a creator).  Although two of the most popular forms of the argument (horizontal and vertical) agree that an infinite regress can’t get around a first cause, or creator, they have different reasons for saying so.

The popular atheist Richard Dawkins, a scientist who has been taken to task even by some fellow atheists for his often-unsatisfying philosophical reasoning, made this mistake when he (unwisely) took on Thomas Aquinas. Commenting upon several arguments from Aquinas’s “Five Ways,” Dawkins concluded that, “These arguments rely upon the idea of a[n infinite] regress and invoke God to terminate it. They make the entirely unwarranted assumption that God himself is immune to the regress” (The God Delusion, p. 101). One of the problems with Dawkins’ case here is that he presents Aquinas’s “vertical” cosmological argument forms as if they were of the “horizontal” type. Aquinas, in fact, had no problem with the idea of an infinite series of independent causes – he only objected to there being an infinite causal chain with no efficient (first) cause (see Summa Theologiæ I. Q.46, A.2).

The most popular cosmological argument today is the “horizontal” or Kalam cosmological argument. It argues that the existence of the universe is an effect, whose cause is God, the creator:

1. Everything that begins to exist has a cause of its existence.
2. The universe began to exist.
3. There cannot be an infinite number of causes.
4. Therefore, the universe has a first cause of its existence (God).

The heart of this argument lies in the impossibility (premise 1) of an infinite regression of causes or events. An actual infinite number of things cannot exist because an “infinite number” is a contradiction, nowhere observed in nature. If the universe had no beginning, then the number of causes or moments before today would be an infinite amount of moments – but there cannot be an actually infinite amount of moments, so the universe must have begun and was therefore caused to begin by something uncaused (and outside the universe). This cause is God.

The above problem of an infinite regress has sometimes been incorrectly applied to other cosmological arguments like the contingency (“vertical”) argument based on the writings of St. Thomas Aquinas. Aquinas, however, actually denied the validity of arguing for the beginning of the universe based on an infinite regress! His “vertical” cosmological argument is actually making a completely different claim than the “horizontal” version:

1. At least one contingent being (i.e., an existing being whose existence is not necessary, or who could possibly not exist) exists.
2. Contingent beings must have an external cause of their existence.
3. An infinite number of contingent beings cannot account for the existence of all contingent beings.
4. Therefore, a necessary being (a being that cannot not-exist) exists (God).

The key issue is that even an infinite number of contingent beings cannot ultimately explain the existence of a single contingent being (in the same way that positing an infinite number of train cars does not explain the motion of the first train car—there has to be an engine). The problem is not that there cannot be an infinite number of things (Aquinas argued that there could be). Rather, it is that even an infinite number of contingent beings could never ultimately account for itself.

Familiarity with these kinds of arguments allows one to respond with precision, which in turn helps make dialogue fruitful. While it may seem nit-picky to insist on such precision, terminology is important because words and ideas are intertwined. Confusion about how these arguments work can have negative and long-lasting effects. Even simply confusing two types of arguments that fall under same general category can make them seem to lack the support or strength they actually have. This, in turn, could lead to an unwarranted abandonment of a reasonable conclusion—in this case, that God the Creator exists.

Now that we have cleared up a popular confusion over two popular forms of the cosmological argument, in the next article we will look at arguments from design.