A Simple Argument for God’s Existence

Post Author: Bill Pratt

A couple months ago, we featured a 7 minute audio clip from philosopher Peter Kreeft’s lecture on arguments for God’s existence.  For this post, we are presenting an additional clip from the lecture – this time on the first cause argument for God’s existence.  Again, Kreeft does a wonderful job simplifying the argument so that anyone can understand.  Enjoy!

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  • Tim

    This argument has never been a very strong one for me. If God can be an uncaused first cause, then why can’t the big bang be an uncaused first cause?

    He appeals to our sense of intuition to show that there cannot exist a universe that has always existed, but how many times has science shown us that our intuition about reality is wrong? Quantum physics tells us the properties of a particle do not exist until observed – this principle of quantum physics is highly supported by experiment, but extremely unintuitive.

  • Bill Pratt

    How could experimentation show us that a particle doesn’t exist until we observe it?

  • Tim


    First let me say that I do believe in God – it’s just I don’t think this is a strong argument for his existence.

    The EPR (Einstein-Podolsky-Rosen) paradox experiments show us that the properties (such as momentum, spin, polarization) of a particle are determined at the time of measurement, and not by a “local determinstic theory”. This is an extreme departure from the concepts of “classical physics” where the physical world is deterministic. Einstein in fact argued strenuously for an intuitive interpretation of reality, and formulated this EPR paradox to show how bizarre quantum mechanics really was. In the 60s a guy named John Bell made it possible to test Einstein’s paradox, and all experiments done since then have confirmed Einstein was wrong about this subject – and quantum mechanics is right.

    So I hesitate to rely on the “reality must conform to our intuition” argument. Again, why can’t the big bang be an uncaused first cause? At the point of the big bang even physicists agree that normal physical laws (including causality) break down, so it would seem to be possible for the big bang to not have to conform to causality, and thus be “uncaused”.

  • Bill Pratt

    Thanks for the response. My basic understanding of quantum mechanics is that sub-atomic particles behave like wave functions and that these wave functions behave probabilistically. When we attempt to measure the position of one of these particles, the particle settles into one of the possible quantum states described by the wave functions. There is substantial debate among physicists and philosophers of science over how these results are to be interpreted.

    When you say that observers bring particles into existence, this represents one of the many interpretations of quantum mechanics, and thus is not a viewpoint that commands wide assent within the scientific community. In fact, I would say this language is highly problematic. In all the double slit experiments I’m aware of, the existence of the particle is not questioned, but its position and other properties. Maybe there are more experiments that I don’t know about?

    Having said all that, I agree with you that quantum mechanics has shown that sub-atomic particles behave differently than what we would expect from the laws of classical physics that we use to describe the super-atomic world. That is certainly true. But does quantum mechanics force us to toss out the law of causality? I don’t think so, and I believe that anyone arguing that way will have a tough time making their case.

    When you say the big bang could be the first cause, I’m not sure what you mean. The first cause must have always existed, but scientists tell us the big bang occurred 13.8 billion years ago. So what came before the big bang? Or are you saying that the big bang has always existed? And what exactly is the big bang? I thought it was just words used to describe an initial explosion event, but you seem to be saying that the big bang is some kind of causal agent, a thing that exists eternally and that can act to cause the universe.

    Sorry for all the questions. I’m just trying to get your point of view, so I hope you’ll be patient with me.

    Thanks so much for the conversation,

  • Tim


    To quote from wikipedia: “Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past. This singularity signals the breakdown of general relativity.”

    To ask “what happened before this point of infinite density?” isn’t a well-defined question, because the laws of physics have broken down at this singularity, and we can’t extrapolate further into the past beyond it.

    You also seem to be saying that any uncaused first cause must have “always existed”, but for anything (God, the big bang, etc..) which is not subject to causality (and thus outside of time) the concept of “always” is related to time and thus not well-defined here.

    You can only really say that the uncaused first cause existed at the beginning of time. To ask “what happened before the beginning of time?” is not well-defined, as it refers to the concept of “before” which is dependent on time.

  • Bill Pratt

    I am saying that the first cause cannot not exist. It must be a necessary being. But big bang theory tells us that the universe came into existence 13.8 billion years ago, so that rules out the universe as a necessary being, for it came into existence. The universe is capable of non-existence. So I don’t understand how the universe can be the first cause.

    If science showed us that the universe has existed forever (which is what many scientists thought until the 20th century), then you have some kind of a case that the universe could be the first cause, but that just isn’t the case. I hope you can see how counter-intuitive it is to claim that something that came into existence 13.8 billion years ago is the first cause of all that exists.


  • George

    Do you know anything about this Bill?

    “There is a point in time called the “Planck time” (after the late physicist Max Planck, one of the pioneers of quantum mechanics) before which our ability to infer the behavior of the universe on the basis of general relativity alone is destroyed. The problem is that prior to the Planck time, the universe is so small that quantum mechanical effects become very important. Therefore, a correct description of the behavior of the universe prior to the Planck time requires a synthesis of quantum mechanics and general relativity–a theory of quantum gravity, in other words. And to this date, no full theory of quantum gravity has been developed, much less attained the consensus status that post-Planck-time Big Bang theory enjoys. Without such a theory, we cannot draw from cosmology any conclusions about whether the universe had a beginning or not”

    “Do we expect the theory of general relativity to break down in the extreme conditions near a spacetime singularity? The answer is yes. We know that on a microscopic scale, nature is governed by the laws of quantum theory. However, the principles of quantum mechanics are not incorporated into general relativity. Hence, we do not believe that general relativity can be a true, final theory of nature. Classical mechanics (that is, Newton’s laws of motion) provides us with an accurate description of the motion of macroscopic bodies, but it breaks down when we attempt to apply it on atomic distance scales. In a similar manner, we believe that general relativity provides an accurate description of our universe under all but the most extreme circumstances. However, near the big bang singularity when the scale factor a goes to zero and the density and curvature become infinite, we expect general relativity to break down.”

    Here’s a link to the entire article if your interested http://www.infidels.org/library/modern/mark_vuletic/bigbang.html

  • George

    Why the Cosmological argument fails

  • Bill Pratt

    Thanks for the link. The existence of a quantum field before the Big bang is hardly something that physicists are agreed upon, and I don’t even see how they could ever prove its existence (see this blog post on the quantum creation of the universe). It is a hypothesis at this point that cannot be confirmed by observational evidence. But, let’s say that there is a quantum field that existed before the Big Bang. Where did that come from? If you posit another entity, then I just keep asking the same question. At some point, we need a being whose existence is uncaused, that exists necessarily.

    Look, the atheists can always escape by claiming that some natural thing, like the quantum field, has always existed, thus countering the cosmological argument. But that natural thing that the atheist posits requires just as much faith as belief in God, if not more. The eternally existing quantum field is not provable by science. Are atheists reduced to giving non-scientific answers to the origin of the universe just to avoid God?

  • george

    HI Bill

    Sorry been really busy lately, thanks for the great response!

    God Bless

  • Rob

    I know god exists. And so does every other human being, because there is good evidence for universal belief.
    I think the main reason we all go to church services is to know God; to know what He wants from us, and what we can do for Him.
    Mr Kreeft’s definition of God is pretty grand; about as grand as anyone could possibly imagine, then double it!
    Sorry, but this definition seems based more on “maximum possible grandness”, rather than any serious exploration of who or what God really could be.

  • Mulkaaustin

    Tim, in order for something to be “uncaused” or immovable, as I would say, it must be eternal. Thus, if it is eternal it becomes unable to be moved or created by anything else. Since the big bang implies a beginning, it cannot be eternal. Thus, it would be impossible for something that came into existence to be eternal.

  • Andrew Ryan

    The big bang is the cause of our present universe, not the cause of everything.