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A Beginner’s Guide to the Kalam Cosmological Argument 🌶 🌶 🌶 🌶🌶

The Kalam cosmological argument was originally put forth by a twelfth-century medieval Muslim philosopher from Persia (modern day Iran) by the name of Abu Hamid Muhammad ibn Muhammad al-Ghazali. Al-Ghazali was concerned by the influence of Greek philosophy (which maintained a beginningless Universe – one which flows necessarily out of God) on the Muslim philosophers of his day. Al-Ghazali published a critique of this teaching in a book titled The Incoherence of the Philosophers, in which he argued that the Universe must have a beginning. And if the Universe had a beginning at a point in the finite past, then there must be a transcendent Creator who brought the Universe into being – since nothing begins to exist without a cause. As al-Ghazali put it:

“Every being which begins has a cause for its beginning; now the world is a being which begins; therefore, it possesses a cause for its beginning.”

We can thus summarise al-Ghazali’s reasoning in three basic steps:

  1. Whatever begins to exist has a cause.
  2. The Universe began to exist.
  3. Therefore, the Universe has a cause.

This argument uses a form of reasoning that philosophers call deduction. In this style of argument, a conclusion necessarily and inescapably follows from the premises – provided, of course, that those premises are in fact true.

The first of those premises – whatever begins to exist has a cause – seems to be almost indisputable. After all, something cannot simply pop into being uncaused. The principle of causality – that effects are always produced by causes – is what undergirds the scientific endeavour. In every realm of experience, new things are brought into being by causes.

A sceptic will often reply to this point by claiming that in physics it is theorised that subatomic particles can come into being out of nothing. However, such theories concern particles originating as a fluctuation of the energy contained in a vacuum. A vacuum, in physics, is a sea of fluctuating energy that is governed by physical laws. When we are talking about the origins of the Universe, however, we are asking where the physical laws that govern the material world – as well as where matter itself – comes from.

Another typical counter that an atheist lacking sophistication might reply with is that if everything requires a cause, then what is the cause of the Creator? Notice, however, that premise 1 of the argument does not state that everything has a cause for its existence. Rather, it states that everything which has a beginning has a cause for its existence. This is a rather different claim. If God is conceived of as eternal – that is to say, timeless – then He does not fit into the category of things that begin to exist, and thus does not fit into the category of things requiring a cause. Ultimately, every worldview must posit an unmoved mover, something which exists out of the necessity of its own nature – a timeless, uncaused, necessarily existent being responsible for initiating the chain of cause and effect. Otherwise, one is forced to postulate an infinite regress of causal explanations. The Universe clearly is not the unmoved mover from which everything else comes, since the scientific evidence shows convincingly that our Universe began to exist around 13.8 billion years ago. On top of that, various philosophical arguments establish that an infinite regress entails logical absurdity.

Let us now turn our attention to the second premise of the argument, namely, that the Universe began to exist. There are two sets of argument that firmly establish the truth of this premise – those are philosophical arguments and scientific arguments.

Let’s begin by considering the philosophical arguments. Al-Ghazali pointed out that if the Universe is infinite in the past – that is, it never began to exist – then there must have been an unlimited number of past events prior to the present. But, Ghazali argued, an actual infinite number of things entails logical absurdity. Notice that there is a difference between an actual infinite number of things and a potential infinite. For instance, any finite distance can be divided in half, and then quarters, and then eighths, and so on to infinity. The number of divisions is what we call a potential infinite, since in principle one could go on dividing and dividing and dividing forever. You would never arrive, however, at an actual infinite number of divisions. You would always have divided the distance a finite number of times.

Al-Ghazali pointed out that if an actual infinite were possible, various absurdities were entailed. For example, imagine that you have a string of numbers from 1 to infinity. Suppose you were to remove all the numbers greater than or equal to three (that is, an infinite number of numbers). How many numbers do you have left? The answer of course is two. Now suppose that instead you were to remove all the odd numbers. How many numbers do you have left now? The answer is infinity. Thus, a contradiction is entailed – infinity minus infinity is equal to two and infinity minus infinity is equal to infinity. These are the sorts of logical contradictions entailed when we try to treat infinity as an actual number.

Besides the philosophical reasons to think the past is finite, there is also a plethora of scientific evidences that have pointed forcefully in this direction. For most of human history it was taken for granted that the Universe as a whole was unchanging. While things that were in the Universe itself were changing, the Universe itself was just there. Albert Einstein too held this view, but he found this understanding challenged by his general theory of relativity. Einstein’s equations described a Universe that was blowing up like a balloon or else collapsing in upon itself. Uncomfortable with this idea, Einstein manipulated his equations by adding a fudge factor known as the ‘cosmological constant’, a mistake that Einstein later described as ‘the greatest blunder of his career.’ In the 1920s, the Belgian astronomer Georges Lemaitre and the Russian mathematician Alexander Friedman independently developed models of an expanding universe, based upon the equations of Einstein. In 1929, the American astronomer Edwin Hubble discovered, through his observations at the Mount Wilson Observatory, that the light from distant galaxies, in every direction of the sky, appeared to be redder than expected – a phenomenon now known as “redshift”, which is best explained by the stretching of light waves as galaxies move away from us.

In order to get a better handle on what is going on, imagine a balloon with painted black dots over its surface. Imagine what would happen as you blow up the balloon. As the balloon (representing the Universe) gets bigger and bigger, the painted dots (representing the galaxies) grow farther and farther apart. Now imagine that somebody videotaped you blowing up the balloon. Rewinding the tape would reveal that as you go back in time the black dots get closer and closer together. The balloon cannot have been expanding forever. So it is with our Universe. Eventually, as the tape of the Universe is wound back, the Universe comes to have zero spatial volume. This is just one of various lines of scientific evidence that reveal our Universe began to exist.

Since the two premises of the kalam cosmological argument are true, the conclusion necessarily and inescapably follows – namely, that the Universe has a cause for its existence. What can we say about this cause? As the creator of time, space and matter itself, this cause must transcend space and time. That is to say, the cause must be transtemporal, spaceless, and immaterial – a description that rather befits what enters most people’s mind when they think of God. I will conclude by quoting the late agnostic astronomer Robert Jastrow, from his book God and the Astronomers:

For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountain of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.

Indeed, long before modern astronomy discovered powerful evidence of a cosmic beginning, the text of the Bible had stated for thousands of years that “All things were made through [Christ], and without him was not any thing made that was made,” (John 1:3).


Dr Jonathan McLatchie is a writer, international speaker and debater. He holds a Bachelor’s degree (with Honours) in forensic biology, a Masters (M.Res) degree in evolutionary biology, and a second Master’s degree in medical and molecular bioscience and PhD in cell biology. He is Assistant Professor of Biology at Sattler College.

Further Reading:

Beginner: A Faithful Guide to Philosophy by Peter S. Williams
Intermediate: Philosophical Foundations for a Christian Worldview, William Lane Craig & J.P. Moreland
Advanced: The Blackwell Companion to Natural Theology, William Lane Craig & J.P. Moreland (editors)