Tuesday, July 17, 2007

The Unmoved Mover

Another old post revived; my Philosophy 101 class is going over Aristotle and Aquinas:

In St. Thomas Aquinas' Five Ways, we find the most evident way is the argument from motion, establishing the existence of an unmoved mover. Let me present a version of the argument as follows:

1. At least one thing, call it X, is in motion.
2. If X is in motion, then its motion must be caused.
3. If X's motion is caused, then the cause of that motion must be either a) a series of movers which are themselves moving or b) a series of movers that contains at least one unmoved mover.
4. A series of moved movers, even if it is an infinite series, cannot explain the motion of X.
5. Therefore, the motion of X must be explained in terms of the existence of an unmoved mover.
6. That which does not move but causes the motion of all other things deserves to be called God.
7. Therefore, God exists.

If we look at this argument, premise 1 seems undoubtable. Let us grant that the motion of X must be caused. The options in 3 look exhaustive. I'm going to grant 6 for the sake of argument. Mind you, we're a long way from John 3:16. But it does lead us in the direction of a belief in something non-physical on which the universe depends. But how about 4. Why does 4 seem unsatisfactory?

Well, put something somewhere, say, a five-dollar bill on top of your dresser. Now come back the next day, and see if it is still there. If you see it still there, you don't need an explanation. It is where you expected to find it. If it is gone, we need an explanation. Somebody removed the bill. So, we are inclined, at least initially, to suppose that rest needs no explanation, but motion does. Hence an infinite series of moved movers doesn't do the explanatory job needed, and you need an unmoved mover.

Or do you? Perhaps we think this way because we are accustomed to living in a gravitational field, called planet earth. But if we didn't live in a gravitational field, but lived on the space station, we would expect things to be moving, and we would have to explain why things get stopped.

So the idea that motion stands in special need of explanation, while the absence of motion does not, is an idea that modern science seems to reject. Without this assumption, the argument to the Unmoved Mover fails.

Or does it? Are there any good Thomists (followers of St. Thomas Aquinas) out there who can explain to me what I might be missing?


Dennis Monokroussos said...

I think there are two possible ways to fix the argument. First, I've heard that motus (motion) can refer to change generically, not necessarily what's translated as local motion.

If that's not so, or if it is but doesn't apply here, that's fine; let's just say Aquinas's argument is wrong as stated, but can be improved by substituting change or even accelerated motion for motion.

Victor Reppert said...

Thanks, schachmeister. But I'm not sure this helps. Even if we assume that motion refers to change generically, the argument is still left assuming that change needs explanation, while the lack of change does not. Why?

Brandon said...

I'm not sure I understand what you mean by (4).

I've written two posts roughing out my thoughts on the subject of the First Way:

Aquinas's First WayFurther Thought on Aquinas's First WayMy thought is that the actual claim Aquinas is trying to make is that supposing an infinite series of moved movers entails a contradiction, given the sort of dependence involved.

Dennis Monokroussos said...

You tricked me! The way you framed the issue in the post suggested that your concern with the premise had to do with the effect of post-Newtonian science on Aristotelian physics, not with the justification of some version of the principle of sufficient reason. Is that what you're getting at?

Dave said...

Another great post!

There is a much fuller version of the argument in the Summa Contra Gentiles (Book I, Chapter 13) in which Thomas summarizes Aristotle's proof that whatever is moved is moved by another. It's very elaborate and difficult to understand. Etienne Gilson's attempt at explaining it in his book The Christian Philosophy of St. Thomas Aquinas is no more clear than the original. So, I won't even bother to reproduce it here, but anyone who's interested can look at Amazon or in your local Borders or Barnes and Noble for Aquinas' lesser known summa.

Having brushed Thomas own defense off, which I may regret, let me offer a defense of my own of Proposition 2. I'm not confident in this at all, but it's a line that occurred to me.

1. Some things are in motion.
2. Whatever is in motion is in motion either necessarily or accidentally.
3. But at least some things which are in motion are not in motion necessarily for
----a. Whatever exists necessarily in a certain state will always exist in that state.
----b. If a thing were necessarily in motion, it would always be in motion (from a).
----c. Some things in motion, however, cease to move.
----d. Those things that cease to move, therefore, cannot be in motion necessarily (from a & b).
4. Therefore, some things are in motion accidentally.
5. Whatever is in motion accidentally has received its motion from some cause or from no cause.
6. But nothing can be received from nothing.
7. Therefore, whatever is in motion accidentally has been caused to be in motion.

Now, this "proof" was a quickie and it would not surprise me in the least if I made several formal and informal errors somewhere, so please be gentle with me. The important thing to note is that the argument does not state that everything has its motion caused by something, but only the more modest claim that some of the things which are in motion clearly do not possess that attribute necessarily, and therefore must have had their movement caused.

By way of defense of some of the specific propositions, I would note that 3c. is, like proposition 1 in the original argument, evident from the senses. Proposition 5 clearly rests on the assumption that any attribute which something possesses accidentally must have been caused, and proposition 6 is basically a restatement of "ex nihilo nihil fit".

I'm suspicious of this argument, but, hey, why should that stop me? If it works, it shows that there are some things in motion which have had their motion caused. These things, therefore, if the First Way is correct, point to an Unmoved Mover, even if it cannot be proved that all things in motion point this way.



Victor Reppert said...

Just responding to Dennis here, for now. My idea was that the weight of our experience appears to support the idea that motion needs explanation but the lack of motion does not need explanation, but when we look more closely we find that this is because we all grew up on a gravitational field. Without that experiential bias, we have no reason to believe that motion cannot be the ultimate brute fact as opposed to the lack of same.

I will have ot look closely at Brandon's and David's comments and let you know what I think.

Jason said...

I don't know if this makes any difference to the argument, pro or con; but I observe that (so far as we can now tell) there are in fact no unmoving physical objects. The computer you're looking at, for instance, is moving through physical space in almost a dozen ways I can think of offhand (continental drift, planetary rotation, planetary revolution, axis circling, solar system orbiting, galaxy within a cluster, universal expansion, etc.); and is totally comprised (barring absolute zero temperature?) of moving particles.

Meanwhile--interesting critique of the classical argument, Vic. Looks like some good merit to it; though I've always figured Aquinas' argument (as with any version of the CosA) works better regarding causation simpliciter, rather than movement in particular.

shulamite said...

Moved movers, by definition, are moved by another. What is moved by another has its motion explained by another.

What is so strange about giving a cause of motion to a moved mover? This is simply to recognize what the word "moved" means.

There is no problem, then, with your premise #4.

hiddehghost said...

Some galaxies in space have been observed as not moving from their position in space. The core has no movement from it's position though the arms of a galaxy may swing in an orbit around it's core.

hiddehghost said...

Whoops, I also meant to write that the current cosmological theory is that there are black holes in the center of those stationary galaxies.

HV said...

Newton's First Law is in conflict with Aristotle's theory of motion, but I think modern physics may open a new door to arguments about a first cause. There is a program in theoretical physics to unite general relativity and quantum mechanics called quantum geometry. It is less well known than the other major program, string theory. As I mentioned in a comment on the Templeton Foundation post, don't ask me to explain the theory, since I am just beginning to read about it. From what I can gather it is a theory of a timeless, spaceless mode of being that underlies our temporal, spatial mode of being. As such it would appear to be the timeless cause of everything in time. So it would be a "first" cause in a timeless sense. We could say it would be a first cause "in principio, et nunc, et semper".

Steven Carr said...

Victor writes 'Even if we assume that motion refers to change generically, the argument is still left assuming that change needs explanation, while the lack of change does not. Why?'

Because that suits the apologetic at that particular moment.

If apologists want to say that lack of change needs explaining they will demand of atheists an explanation of why, for example, the fundamental properties of electrons do not change with time.

See http://maverickphilosopher.powerblogs.com/posts/1125109986.shtml 'Thus at any time the regularity of nature has no explanation.' and Swinburne demands an explanation from naturalists of something that at other times, apologists say needs no explaining.

Jason said...

Actually, the explanation is probably simpler than that: most philosophers (whatever their theological stripe or lack thereof) are privative aseitists.

It wasn't that the notion of 'a lack-of-change requires no explanation' was a handy apologetic tactic. Everyone of note agreed with that already, in Thomas' day. Most people still do.

Dawkins' analysis of Swinburne could have been better; but yes, S. makes a mistake there (and BV after him): the explanation for why electrons have the properties they do, is ultimately because the IF made/produced them that way (whether the IF is naturalistic or supernaturalistic, sentient or non-sentient). Electrons aren't "brute facts"--they aren't a bunch of IFs, but are derivative entities. Whichever route we go, so long as we are proposing one IF (i.e. not an infinite regression or a cosmological x-ism), then there is (practically by tautology) only one entity which can with any reasonableness be classified as a "brute fact".

S. is making an unnecessary step in his attempt at simplicity, and Dawkins (though somewhat ineptly) rightly nails him on a technicality. Which could be extended (as D may in fact have done in his review) by noting that if an electron had properties different from what it does, then it would simply be something else instead of an electron (a positron for instance); or else it would simply be classifiable in varieties (like various quarks, all of which are quarks but which behave a little differently).

S. and I wouldn't always get along very well, I suspect. {g} (He'd keep out of such mis-steps if he went positive aseity instead of privative... Priv-asei isn't Christian theism anyway.)


Edward T. Babinski said...

I'd like to piggy back on Steven Carr's remark above, and simply point out that all philosophies start with a bit of reality, never the whole, and then they spend the rest of their time explaining how that bit of reality gave birth to the other bit that was left out in the first place.

Take motion and non-motion. The cosmos contains examples of both, relatively speaking, so far as our brains envision and name such things, which itself raises questions of epistemological truth. But think about this, does anyone really know what something such as "absolute non-motion" or "absolute motion" might "be?" Not really. You can start with either, and then philosophy's job is to simply add on the other half (and in this case call it a "proof of God," quid pro quo). That's philosophy for you.

Or take good and evil, pleasure and pain/suffering, happiness and sadness. The cosmos contains both. So let's say you start with one, let's say you start with "absolute goodness," and then you have to get from that to "pain, suffering, and sadness." One might just as easily and philosophically imagine an ALL BAD creator and one might argue that this ALL BAD creator designed a cosmos of pitiless mechanism and of such immense size as to leave a huge pit of doubt and despair in the stomachs of beings he created solely to enjoy their doubts and pains, both mental and physical, always providing them with just enough incentive to keep going on with their lives and hoping wonderful things, but to see it always and everywhere end in death, the deaths of countless species over time in the ground beneath our feet, the deaths of exploding stars and black holes, and colliding galaxies, all around us. This DARK CREATOR is as inventive in his ways to torture us both mentally and physically as he is inventive in giving us each just enough reason to keep going on each day, hence he gets to milk or harvest evil, suffering and pain in all of it's varieites.

Now you see how useful philosophy is! It can explain literally everything, in a variety of ways.

But sleep on it first. Let your major brain modules disconnect and fall into dreamless unconsciousness, apparently a realm that philosophers haven't yet conquered, since I haven't yet seen "The Argument from Having to Spend a Third of Our Lives in A Dreamless Unconscious State."

I'm not mocking, I'm thinking. Think of my comments as guerilla ontology, not atheism, since I really don't know about things "as a whole."

It's not I but Christian philosophers who argue that eternally punishable evil arose out of the equally eternal and originally perfect creative will of an absolutely good Being who is in an of everything in His creation and even announced that it all was "good" in the beginning.

Such matters I admit truly are beyond me. I try to stick to simpler things I am able to comprehend more intimately and surely, like the fact that most people agree it's better to be healthy than sick, fed than starving, loved than hated, and intelligent than lacking intelligence. I hope that's not too "zen" for folks in here. I have hopes, at most suspicions, but as of today still no "proofs" concerning things beyond my ken, beyond this life, or in supernatural realms. It does seem however that joys shared are doubled while sorrows shared are halved. That's pretty certain for both individuals who share, and for societies as a whole that we want to increase the joys and lessen the sorrows of.

So many gods, so many creeds,
So many paths that wind and wind,
While just the art of being kind,
Is all the sad world needs.

Ella Wheeler Wilcox (1850-1919)

Victor Reppert said...

The unmoved mover was invented by Aristotle, who certainly had no apologetic motives in mind, since his God was "pure thought thinking itself" and had no interest in human affairs. It's anachronistic to find apologetic motives here.

Aquinas was as much concerned with defending Aristotle as a Christian-friendly thinker as he was of convincing all those medieval atheists that there had to be an unmoved mover.

Platonicus Booknutticus said...

Forgive this very cursory comment. There's nothing more annoying then someone flippantly joining into a discussion that has already progressed several levels beyond what allows casual entrance.

"You're like a child that wanders into a movie in the middle of it and wants to know -"
-Walter (to Donny)in The Big Lebowski

Now, having said that.

Isn't the problem with (4) simply a "traversing the infinite" dillemma?

Or am I outta my element?


Mike D said...

An stationary object requires an unmoving stablizer.

John Umana said...

St. Thomas Aquinas is right after all. All things in the universe are in constant motion.

The most massive explosion of all time occurred 13.7 billion years ago. It is still ongoing. God created the physical Universe with an incredibly white-hot and fast-moving explosion from nothingness, the Big Bang. The temperature of the fireball was 100 million trillion trillion degrees. At one and the same time, God created the fabric of space-time, matter and energy, from the singularity forever expanding outwards. The cooled-down remnants of this blast, microwave astronomers can still observe today throughout the Universe.
When we think of the Big Bang as starting from the size of a fist or even a needle point, we are still off the mark. The Big Bang started from nothing, less than the size of the period at the end of this sentence. Even the period at the end of a sentence occupies a tiny bit of space, but before Creation there was no space or time in which to place a fireball. Then how could God create the entire expanding Universe from nothingness? How could the entire preemergent Universe fit into less space than the period at the end of a sentence? What caused the expansion? God pictured it expanding forth. Idea precedes Creation. Like a peanut shell, once the bubble of space-time had been created, the expanding fireball was conceived, simultaneously inflating and stretching out space-time with it. The expansion of the cosmos is uniform throughout. Different parts of the Universe do not expand by different amounts.
The theory of inflation, developed in the 1980’s (named after a pun on monetary inflation), correctly maintains that a split second after the Big Bang commenced, there was an extraordinarily rapid expansion of the Universe -- the rather cursory period between 10-35 seconds and 10-33 seconds post-Big Bang. With rapid supercooling, the bubble of space-time containing the inchoate cosmos suddenly was driven by an “inflaton field” (correctly spelled) to expand exponentially. Picture this -- in less than one millionth of a trillionth of a trillionth of a second, the entire Universe suddenly ballooned out from the size of less than a speck of dust to the vast size of our Milky Way Galaxy. (Our galaxy is about 100,000 light years in diameter.) Triggered by separation of the strong force (the nuclear force that holds quarks together inside of protons and neutrons and tightly packs protons and neutrons into the atomic nucleus), gravity which normally pulls objects towards each other, became a massive repulsive energy. The tiny Universe increased in size by a factor of 1030 to 10100 or more in this infinitesimal instant than in the 13.7 billion years since. Talk about a big blast! This superaccelerated expansion of the fabric of space-time for an exceedingly brief instant far outran even the speed of light. Not to worry, though. The speed of the expansion of cosmic space does not disturb Dr. Einstein’s theory of special relativity, which applies only to motion through space, not to expanding space.
Supreme Creator’s first pitch of the baseball season was a fast ball clocked at millions of trillions of times the speed of light! Yes, the pitch was right in there for strike one! And the cosmos was off to an exciting start! But like any great pitcher, Supreme Being did not just sit back after the first pitch and let the cosmos unwind on its own. There were many heavy hitters coming up to bat, rubbing the rosin bag against the grip and gritting their teeth in anticipation.
After that rapid ballooning out for less than a billionth of a second, space continued to expand and cool at a much more leisurely pace. As the cosmos expanded, it rapidly cooled from the intense heat of its birth. Under inflation cosmology, quantum fluctuations in the Universe’s pre-inflationary kernel would have been blown up to astronomical scales in the formation of galaxies and clusters as the cosmos expanded. But, as we shall see, far more was involved in the overall structure of the cosmos and the formation of galaxies, stars and planets than haphazard quantum perturbations.
In the initial fireball, the strong and weak nuclear forces and the electromagnetic force were undifferentiated. Atoms did not yet exist. The first types of “particles” were of two types, fermions (leptons and quarks) and bosons (the X-particles, gluons, vector mesons and photons). They would lead to the creation of everything we observe on Earth, in the sky and space, and to the creation of life that exists throughout the Universe.
The first few moments of the super-heated fireball produced the lightest elements. One second after the Big Bang, the temperature of the Universe had cooled down to a balmy 10 billion degrees. It was filled with neutrons, protons, electrons, anti-electrons (positrons), photons and neutrinos. As the Universe cooled down within a minute from this searing heat, the neutrons either decayed into protons and electrons or combined with protons to make a hydrogen isotope known as deuterium. During the first three minutes of the Universe, most of the deuterium fused to make helium. Trace amounts of lithium were also produced at this time. This process of the formation of the light elements in the infant Universe -- hydrogen, deuterium, helium-3, helium-4, and lithium-7 -- is called “Big Bang nucleosynthesis.” After three minutes of nucleosynthesis, the temperature and density of the nascent Universe fell below that required for nuclear fusion for a stretch of time.
About 300,000 years later, the Universe having cooled down to 3,000 Kelvins, electrons mated with atomic nuclei to form atoms. The Universe became transparent to electromagnetic radiation, and began emitting cosmic background radiation that is observed today in the microwave spectrum. The overall temperature of the cosmos has continued cooling over time.
About 200 million years after the Big Bang, nuclear fusion kicked in and eventually produced the heavier elements. Elements heavier than lithium were all manufactured in stars and with the explosion of those first stars blasted out far into interstellar space. During the late stages of stellar evolution, massive stars fuse helium to form carbon, oxygen, silicon, sulfur, and iron. Elements heavier than iron are produced in the outer envelopes of super-giant stars and blasted into interstellar space in the explosions of these stars known as supernovae. The first moments of the Big Bang created principally hydrogen (mass 1) and helium (mass 4), because there are no long lived atomic nuclei with mass 5 and 8 to make the bridge to heavier elements such as carbon (mass 12). But in stars the formation of carbon is possible through the “triple-alpha reaction” where three helium nuclei (alpha particles) fuse under intense heat to form a nucleus of carbon-12. All carbon-based life forms on Earth and elsewhere in the Universe are composed of such carbonaceous stardust formed deep within the interiors of stars. The Universe cooled as it expanded and has continued to cool.
But even before formation of stars, the ambient gas in the Universe had been ionized by the first 200 million years after the Big Bang, due to ionizing radiation from a population of primordial black holes. Black holes -- gravity implosions of dead stars of at least 5 to 20 solar masses -- are the device for organizing the Universe, as we shall see. They are commonplace throughout the Universe, though (indirectly) observed only in the last ten years with NASA’s Hubble Space Telescope and other observatories.
(excerpt from Creation: Towards a Theory of All Things, John Umana)

Anonymous said...

Forgive the intrusion.

To properly understand Aquinas' argument I really suggest purchasing a recent translation of Aristotle's Physics, as well as Aquinas' Commentary on The Physics.

To really beat it to death, you will probably also need a copy of Aquinas' Commentaries on On Interpretation and Posterior Analytics handy.

A good supplementary text by a very good Aristotelian, now deceased unfortunately, is Aristotle: A Contemporary Appreciation by Henry B. Veatch

You'll also want to have a decent reference to the Pre Socratics and Platonic thought that Aristotle is criticizing to make sure you are following all the nuances.

Most of the decent Thomist natural philosophers are getting on in years or deceased, but this should get you started:




Edward T. Babinski said...

Employing "God" to explain the mystery of the cosmos is simply to compound mysteries/questions.

And judging by how the cosmos works, with death and suffering, what type of "God" does that imply?

C. S. Lewis's dreaded finding out after death "This is 'God' deceive yourself no longer."

gnownek said...

I think 4 holds if you accept 2.

I think your objection to something unexpected occuring is simply saying that 2 is not true. And if gravitational field changes occur without a mover then 2 is not true.

Basically aplying this to creation, spontaneous creation is possible or something exists that did not need to be created.

gnownek said...

You seriously teach philosophy?

If something unexpected exists that could move something without being a mover then 2 is not true. 4 holds.

Applied to creation: either creation just came into being or something exists that did not have to be created. Note that 'something' does not have to be God - you could argue that the something that always exists is just some kind of unchanging structure with time existing as a construct of our perception ...

Mind you, God sounds more resonable to me.

Victor Reppert said...

Gosh, I think I teach philosophy seriously. There are plenty of "serious" philosophy teachers who have told their students that all forms of the cosmological argument can be refuted just by asking "Who made God."

Sturgeon's Lawyer said...

#1: Granted. Motion exists, pace Zeno.

#2: Why must motion be caused? This amounts to the presumptuous assumption that the universe must be comprehensible to us.

#3: True, but only because the terms of the proposition are so vague they can encompass anything that might be called a "cause."

#4 is the weakest point in this chain. There is no reason to assume that an infinite regress is not possible.

#5 follows logically once #4 is accepted.

#6: what does it mean to say that this hypothetical UM "deserves" to be called "God"? Either it is God, or it is not. If it is, then "deserving" is irrelevant, and if it is not, then it cannot "deserve" the Name. At any rate, we may suppose, for example, that God created an Unmoved Mover -- a cosmogonical device that never moves, just sits there in Eternity and spawn Big Bangs. Or we may suppose causality is inherent to our cosmos but that the Big Bang, which is our cosmos, does not have any cause, for it is not subject to the rules of the cosmos.

#7, again, follows logically if #6 is accepted.

zinforu said...

I need help to answer this question using 500-750 words. I got stuck. I need to engage the argument which i failed to do on my last assignment. Your help will be greatly appreciated.

What is Aquinas's argument for the claim that there cannot be an infinite regress of motions produced by earlier motions? Is that argument a good one? Defend your answer.

jolly jum said...

The observers awareness takes up the position of local change in the event observed regs c the speed of light. The observers awareness is there for the unmoving thing in the system.