St. Thomas Aquinas vs. Science: the existence of God

 

Saint Thomas Aquinas

As a Doctor of the Church, Thomas Aquinas (born 800 years ago) is considered one of the Catholic Church's greatest theologians and philosophers. He wrote on moral philosophy, virtue ethics and the nature of God (for which he provided five proofs).

I was naturally interested in whether this famous philosopher-theologian might have updated his views in the light of modern science. Thanks to ChatGPT for reincarnating (at least in software) the great intellectual, and thanks to Thomas Aquinas for agreeing to answer my questions.

Q. You gave five proofs of the existence of God in your Summa Theologica. Please list five refutations of these 'proofs' given by modern science, and then give your Thomist response to each of these rebuttals.

A. Certainly. I will present my Five Ways to prove the existence of God as outlined in the “Summa Theologica” and then, in the persona of a modern critic informed by contemporary science, offer refutations. Finally, I shall respond to each of these refutations.

1. The Argument from Motion

My original  argument: Everything that is in motion must be put in motion by something else. There cannot be an infinite regress of movers, so there must be a First Mover, which is God.

Modern Scientific Rebuttal: Modern physics, particularly quantum mechanics, shows that at a subatomic level, particles can move without any apparent cause. Thus, the principle that every motion must be caused by something else is not universally applicable.

My response: The First Mover is not about motion in a physical or spatial sense alone but is about the principle of change and causality in the broader metaphysical sense. Even in quantum mechanics, the behaviour of particles still occurs within a framework governed by certain laws and conditions. The First Mover is the necessary foundation for these laws and the order of the universe, ensuring the consistency of the system itself.

2. The Argument from Causation

My original  argument:  Every effect has a cause, and there cannot be an infinite regress of causes. Therefore, there must be an Uncaused Cause, which is God.

Modern Scientific Rebuttal: The Big Bang theory suggests that the universe could have originated from a singularity, which might not require a cause in the traditional sense. Additionally, the concept of causality might not apply before the existence of time and space.

My response: The Uncaused Cause I speak of is not merely about temporal beginnings but about the very existence of causality and contingency. The Big Bang, if anything, points to a beginning that itself needs explanation. My argument is concerned with the necessity of a cause for the existence of the universe as a whole, not merely its temporal beginning. The existence of contingent beings and events still requires a necessary being, which is God.

3. The Argument from Contingency

My original  argument:  There are contingent beings (things that could either exist or not exist). If everything were contingent, then at some point, nothing would have existed, and nothing would exist now. Therefore, there must be a necessary being whose existence is not contingent, and this is God.

Modern Scientific Rebuttal: The concept of a multiverse or the cyclical nature of the universe (e.g., oscillating universe theory) suggests that our universe could be one of many, and its existence could be part of an eternal cycle without requiring a necessary being.

My response: The multiverse or cyclical models, even if they exist, do not escape the need for a necessary being. Whether we speak of one universe, many universes, or an eternal cycle, the question remains: Why is there something rather than nothing? The existence of any contingent reality, whether singular or multiple, requires a necessary ground of being, which I identify as God.

4. The Argument from Degree

My original  argument:  We notice degrees of qualities such as goodness, truth, and nobility in the world. These degrees imply a maximum, a being that is the source of all perfections, which is God.

Modern Scientific Rebuttal: Degrees of qualities like goodness or truth are subjective and can be explained by evolutionary biology and psychology. What we perceive as "higher" or "better" is a result of social and evolutionary conditioning, not the reflection of a supreme being.

My response: My argument is not merely about subjective human perceptions but about the objective reality of perfection and being. Degrees of qualities presuppose the existence of a maximum, not in a relative sense, but in an absolute, metaphysical sense. Evolutionary explanations can account for relative preferences, but they do not explain the very concept of perfection itself. The maximum degree of being and goodness is not just an ideal but a necessary reality, which is God.

5. The Argument from Design (Teleological Argument)

My original  argument:  The natural world exhibits order and purpose, which implies the existence of a designer. This designer is God.

Modern Scientific Rebuttal: Evolution by natural selection explains the appearance of design in nature. Complex life forms and ecosystems do not require an intelligent designer; they can emerge from simple processes over time.

My response: Evolutionary theory explains the mechanism by which life develops, but it does not explain the origin of the order and the laws that make such processes possible. The argument from design is not merely about biological complexity but about the underlying order and purpose that permeates all of reality. The existence of rational laws and the directedness of natural processes still points to an ultimate Designer, who is God.

In conclusion, while modern science offers valuable insights into the workings of the natural world, it does not negate the metaphysical foundations of my arguments. The Five Ways address the fundamental principles of being, causality, and order, which remain necessary to explain the existence of the universe and everything within it.

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Q. All these rebuttals seem to require (although not to rigorously specify) a God with extraordinary properties of omniscience, omnipotence, moral perfection and so on. This is an extraordinary concept to postulate as an axiom. Particularly when the Big Bang in its low entropy state, as a boundary condition, plus the known laws of physics, can explain all the phenomena we observe, with the exception of human consciousness. So you, Thomas Aquinas, are accused of needless and ungrounded conceptual extravagance in support of your prior agenda of proving the existence of some rational entity you want to call God.

A. Your objection raises an important point: the extraordinary nature of the concept of God as omniscient, omnipotent, and morally perfect. You suggest that postulating such a being is unnecessary, especially when the Big Bang and the laws of physics seem sufficient to explain the phenomena we observe, save for human consciousness.

1. On the Necessity of Postulating God

Indeed, God as I describe is a being of extraordinary attributes, but this is not a conceptual extravagance. Rather, it is a rational inference based on the principle of sufficient reason—the idea that everything that exists has an explanation, either in the necessity of its own nature or in an external cause. The Big Bang, while explaining the temporal beginning of our universe, still presupposes the existence of the laws of physics and a state of low entropy, which themselves require an explanation. Why should these laws exist? Why is the universe fine-tuned to permit life? To claim that these just exist as brute facts without any further explanation is, I suggest, a greater extravagance than postulating a necessary being, whose existence provides the ultimate ground for these realities.

2. On the Attributes of God

The attributes of omniscience, omnipotence, and moral perfection are not arbitrary or needless additions to the concept of God. Rather, they follow logically from the nature of a necessary being. If God is the First Cause or the Necessary Being, then God must be the source of all reality, which implies perfect power (omnipotence). As the ultimate source of truth and order, God must possess perfect knowledge (omniscience). And as the highest good, from which all other goods derive, God must be morally perfect. These attributes are not mere speculations; they are grounded in the philosophical understanding of what it means to be the source of all being.

3. On the Sufficiency of Physical Explanations

You argue that the Big Bang and the known laws of physics can explain almost everything, except human consciousness. I would argue that the very success of these explanations depends on the intelligibility and order of the universe, which points beyond the physical realm to a source of this order. The laws of physics themselves require explanation—why do they exist, and why do they exhibit such mathematical beauty and coherence? Moreover, consciousness remains a profound mystery that physical explanations have yet to fully address. The existence of subjective experience and the human capacity for rational thought suggests a reality beyond mere physical processes.

4. On the Charge of a Prior Agenda

You accuse me of having a prior agenda to prove the existence of a rational entity, which I call God. It is true that my arguments are framed within a theological context, but they are not based on blind faith or a preconceived agenda. Rather, they are grounded in reason and observation. My Five Ways are intended as philosophical arguments that start from what we observe in the world—the existence of motion, causality, contingency, degrees of perfection, and order—and reason to the necessity of a first cause, a necessary being, a supreme perfection, and an ultimate designer.

To dismiss these arguments as mere conceptual extravagance is to overlook the depth of the metaphysical issues they address. The existence of the universe, the laws of physics, and the order we observe all point to a reality that transcends the physical—a reality that is best understood as God.

In sum, the concept of God is not an unnecessary axiom but a reasoned conclusion drawn from the fundamental principles of metaphysics. The attributes of God, far from being speculative, follow logically from the nature of the First Cause or Necessary Being. The physical explanations provided by science, while powerful, still leave us with profound questions about the origin and nature of reality—questions that point to a transcendent source. Therefore, my arguments remain not only relevant but essential in the pursuit of truth.

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The Critic: You are very persuasive, Thomas, yet I fear I am not yet persuaded. However, I thank you for the clarity of your thoughts and for your time.

A: You're most welcome. If you have any further questions or thoughts, feel free to share them. I'm here to help in your pursuit of understanding. Go in peace.