Jerry Coyne and Jim Manzi have been mixing it up lately over the religious implications of evolution. Coyne asserts, quite rudely at times, that evolution disproves the existence of God. Manzi disagrees, and asserts that theism is compatible with evolutionary science.
I’ve had a blog discussion or two with Manzi, and he’s a thoughtful courteous interlocutor. He doesn’t believe that intelligent design is a legitimate scientific inference (so he’s not perfect), but he is logically rigorous and very well informed on scientific matters as well as on the broader philosophical issues. He believes that evolution, understood as an algorithmic process by which populations of organisms change over time, is compatible with belief in God. He asserts that evolutionary science does not demonstrate that atheism is true. He’s right.
Jerry Coyne is another matter. Coyne’s manner is sarcastic and supercilious, or at least as supercilious as one can get without relevant literacy. Coyne is an evolutionary biologist of the first rank, but that is where his competence ends. His arguments against the existence of God are embarrassing, and, like the arguments of Richard Dawkins and other New Atheists, are eliciting a backlash among intellectuals who have at least a modicum of philosophical and theological education. I don’t claim for myself any more than a marginal competence — an amateur’s competence — on such matters, but in refuting Coyne, that’s all that’s necessary.1
Oh dear. This chestnut [Aquinas’ First Way] is so old that it’s fossilized. And the answer to this claim hasn’t changed for decades: why is God any more an “uncaused cause” than is the universe, or the “physical laws” themselves? God is always called the “uncaused cause” without further explanation, but that simply won’t do. If He was an uncaused cause, what did He do before creating everything? Hang around twiddling His thumbs? The people who make this argument are claiming, in effect, that God is by definition an uncaused cause, but we can properly ask “What caused God?” with exactly the same tenacity that theists ask “What caused matter?” And why is God exempt from having a cause, but matter or physical laws are not? This is just sophistry. Faitheist philosophers are always telling us that we don’t grasp the subtleties of theological argument, but that won’t wash here….
Aquinas’ First Way is an elaboration of Aristotle’s argument for the existence of an Unmoved Mover. It is traditionally called the Argument from Motion, but "motion" is the traditional Aristotelian word for what we moderns call change. Motion, meaning translation in space, is only one very limited meaning of classically understood "motion," which refers to any kind of change (e.g., a change in color, a change in shape, a change in temperature, etc.).
The Argument from Motion is based on the observation that all change involves the transition from possibility ("potency") to actuality ("act"). That is, when something changes, it moves from a state of potency for a certain attribute to a state of actuality for that attribute. An acorn is in potency for an oak tree (it is potentially an oak tree). When it becomes an oak tree, it is in act for an oak tree. It’s essential to note that "potency" means that the substance does not posses that attribute, it merely can, under the right circumstances, posses it. No thing can simultaneously be in potency and in act for the same attribute.
When something changes ("moves"), it goes from potency to act with respect to that attribute. But, by definition, a substance cannot change itself, because it lacks the attribute — it is in potency, not actuality. It can’t give itself what it doesn’t have. This is the basis for Thomas' famous dictum:
"That which is moved is moved by another."
It is logically necessary that everything that changes is changed by another. When a substance changes, it begins in potency (without the attribute) and ends in actuality (with the attribute). It cannot give itself the attribute, because, by definition, it is initially in potency for that attribute and doesn't have it to give. It must be changed (moved) by another.
Thomas’ observation is a commonplace. An acorn becomes an oak tree (the actualization of its potency) by the action of radiant heat from the sun, energy and matter from the soil and the air, etc. A tree falls because of the wind. A grass fire is ignited by lightning. Everything that changes is changed by another.
Yet, Aquinas (and Aristotle) noted that the proximate cause of the change (the sunlight, the chemicals in the soil, the wind or lightning) is, generally speaking, itself in a process of change, of transitioning from potency to act. And each change in nature was itself generally the result of change in another substance, and so on. Natural change of this sort is a layered hierarchy of changes — a hierarchy of transitions from potency to act.
The salient question is: can this hierarchy of change — this hierarchy of transitions from potency to act — go on to infinite regress? To understand the answer to this question, it is first important to understand the difference between a series of causes that is accidentally ordered and a series that is essentially ordered.
An accidental series is a series of causes extended in time; it is not essential to the continuation of the series that any of the prior causes remain in existence. The classic example of an accidentally ordered series of causes is a father begetting a son who begets a son who begets… and so on. Aquinas pointed out that this kind of casual series can go on to infinite regress (or at least there’s nothing self-contradictory about it).
But that is not the only kind of change. There are changes — causal series — that are ordered in priority, not in time. That is, there are causal series in which each of the causes must be in existence for the series to be actualized. For example, I use a hammer to hit a nail. The nail changes because it is hit by the hammer; the hammer changes because my hand moved it; my hand moved because my muscles contracted; my muscles contracted because of biochemical changes in my muscle cells; the biochemistry in my muscle cells changed because of action potentials in my nerves, etc.
This kind of casual series in which the series depends on the continuing existence of each component is called an essential series. The components of an essential series depend on the simultaneous existence of prior components. If one one member of the series doesn't exist (the nerve in my arm is cut), then all of the subsequent changes cease. Aquinas (and Aristotle before him) observed that, for an essential series, infinite regress of potency-to-act is not possible.
This is why: in an essentially ordered series of changes, each change depends simultaneously on a change from a prior member of the series. If all members of the series were merely in potency, but not in act, the series could never get started, because potency means lack of actuality. No subsequent "down-the-line" member of an essentially ordered series has independent causal power of its own. So an infinite essentially-ordered series of changes is impossible, because without a first act, it is merely potency (not actuality) all the way down, and nothing could get started. An essentially-ordered causal series must begin with act, not potency. There must be a first member of the series that is in pure act, without potency, or the essential series — the change — would not occur at all. The First Mover in the series must be itself unmoved, because if it were moved — that is, if it went from potency to act — it would necessarily be moved by another, and then wouldn’t be the first member of the series. An essentially ordered casual series must have a First Mover that is itself unmoved.
It's important to point out that Aquinas (and Aristotle) assumed an eternal universe for the purposes of the Argument from Motion. The First Mover is necessary for each and every essentially ordered series of changes in nature. The First Mover is necessary for change occurring at each moment. The argument is unrelated to the Big Bang; as noted, Aquinas assumed (for the sake of the First Way) that there was no temporal beginning of the universe. The argument works irrespective of whether or not the universe had a beginning in time.
The only way to explain change in the natural world is to posit the existence of an unmoved First Mover. Aquinas goes on (in Summa Contra Gentiles and Summa Theologica) to draw out in meticulous detail the necessary attributes of the First Mover, and he demonstrates that it is logically necessary that the First Mover have many attributes (simplicity, omnipotence, etc) that are traditionally attributed to God as understood in the Judeo-Christian tradition. The Argument from Motion is rigorous, and I have merely summarized its salient points, but it is straightforward once the premises are established. It is a very powerful argument. Yet I am not here proposing that Aquinas’s First Way is irrefutable. I believe that it is valid, but thinkers much smarter than I am have debated it for millennia, and still debate it. It is disputed; it has certainly not been refuted. It is a very strong argument, and it has engaged the best philosophers for a very long time.
Enough with philosophical rigor; let’s get back to Coyne. He asserts:
Oh dear. This chestnut [Aquinas’ First Way] is so old that it’s fossilized. And the answer to this claim hasn’t changed for decades…
The philosophical debate on the Argument from Motion (“this chestnut”) has been ongoing for two and a half millennia (since Aristotle). Coyne, for reasons that are obscure, seems to think that the definitive answer was given “decades” ago. Coyne again:
… why is God any more an “uncaused cause” than is the universe, or the “physical laws” themselves? God is always called the “uncaused cause” without further explanation, but that simply won’t do. If He was an uncaused cause, what did He do before creating everything? Hang around twiddling His thumbs?...
Coyne doesn't understand the argument. Aquinas assumed an eternal universe; the First Mover is necessary for all essentially ordered change in the natural world at every moment; it depends not at all on a moment of creation in time. The argument is of course equally valid in a universe with a finite past, but assumptions as to the eternal or finite nature of the past have no bearing whatsoever on the argument. The First Mover is necessary for change at all moments in time; the First Mover is logically necessary once the nature of change is carefully understood.
Furthermore, contra Coyne, the conclusion that a First Mover is logically necessary to explain change in the natural world is the denouement of extraordinarily detailed “further explanation”; in Summa Contra Gentiles, Aquinas devoted hundreds of pages of meticulous philosophical reasoning to the explication of the argument. Coyne again:
The people who make this argument are claiming, in effect, that God is by definition an uncaused cause, but we can properly ask “What caused God?” with exactly the same tenacity that theists ask “What caused matter?”
Coyne can indeed ask what caused the First Mover with “tenacity,” but not with cogency. The logical conclusion of the Argument from Motion is that the First Mover can't be "caused." The First Mover is pure actuality. The First Mover cannot move from potency to act (i.e., "be caused") because it has no potency. Matter (substance) is caused because it has potency; it's not pure actuality. It changes, and thus it is a mixture of potency and act. Matter (substance) cannot be the First Mover, because it's not pure actuality. Coyne:
And why is God exempt from having a cause, but matter or physical laws are not? This is just sophistry.
Coyne doesn’t understand the Argument from Motion. The natural world needs a cause that is pure act because an essentially ordered series requires a First Mover that is Itself unmoved. This isn’t sophistry — it’s a detailed logic argument that Coyne doesn’t understand.
Faitheist philosophers are always telling us that we don’t grasp the subtleties of theological argument, but that won’t wash here…
The Argument from Motion was originally made by a pagan (Aristotle), not a “faitheist philosopher.” It has been held by countless thinkers representing an enormous range of metaphysical persuasions. It is an argument that depends entirely on philosophical, not "theological," premises. And if you make a modicum of effort to understand it, it's not particularly "subtle." It's routinely mastered by freshmen in Introduction to Philosophy courses.
There have been brilliant atheists (Hume, Russell, Quine) who have struggled with the profound philosophical issues raised by Aquinas’ Five Ways and by a host of other demonstrations for the existence of God. Their contributions warrant respect, but they have never successfully refuted the classical arguments. These powerful and elegant demonstrations of the necessary existence of a First Cause have been set aside by stipulation, not by refutation. It is merely fashionable to deny them. Yet this denial isn’t a denial of the truth of the arguments; it’s a denial of philosophical rigor. It’s a sneer. It now seems that our materialist intelligentsia’s understanding of classical philosophy has degenerated to the point where public intellectuals like Coyne can make arguments that would embarass a teenager in a first semester philosophy course.
Coyne doesn't understand the Argument from Motion. His arguments are too uninformed to even be sophistry. He’s all spittle. But there are people who do understand, and they’re taking notice. Thanks to the high public visibility of New Atheists like Coyne and Dawkins and Harris and Hitchens and Dennett, the anti-intellectual nature of New Atheism and the sheer malignity and fatuousness of what passes for New Atheist thought is becoming increasingly apparent to those who are paying attention to this debate. Many non-theists are cutting ties with New Atheism. The damage that Coyne and other New Atheists are doing to their own atheist cause is incalculable.
1 For a marvelous expert discussion of the New Atheists’ philosophical incompetence and a superb introduction to the Aristotelian/Thomist approach to arguments for God’s existence and the application of Thomism to modern science, I heartily recommend Ed Feser’s book, The Last Superstition. Feser, an academic philosopher and a Catholic who was converted to Christianity from atheism by the force of Thomist arguments, has a gift for exposition. The Last Superstition is one of the best books I’ve read in a very long time.