Friday, April 30, 2010

Reply to Dr Torley

Dr Torley has responded to my series on Intelligent Design theory once more, and very graciously. I have to note how impressed I am at the politeness of someone who's been pondering these topics for many years to my reflections and objections, when by my own admission I've only begun thinking about the subject in earnest in the last few weeks. It's always irritating for an expert or an old hand to deal with upstarts who think they know everything, and I appreciate everyone's patience with me.

Criticizing some of my comments under the heading "The perils of Aristotelian science", Dr Torley writes:

(1) Sullivan writes: “When a rock falls down, it’s acting naturally. It falls down all by itself. When it flies up, this is contrary to its nature.” I am sorry to say that this is incorrect. It’s based on 2,300-year-old Aristotelian physics (as opposed to metaphysics). A rock falls because the Earth’s gravity attracts it, and it flies up because someone or something throws it up in the air. A rock traveling in zero gravity in the far reaches of outer space is still a rock. . . . A rock falls when the force of gravity causes it to fall, and it rises up in the air when another force (e.g. an explosion) hurls it up in the air. A force is a force. Both motions of the rock are equally natural, and they are both explicable in terms of the laws of physics.


I'm sorry that Dr Torley believes that I've never heard of Newtonian physics, but I still wonder if this is right. Is the motion of a rock being hurled upward just as natural as the motion of a rock falling down? If what you mean is "they are both explicable in terms of the laws of physics," then yes, of course. But, as I think the context of my earlier remarks would show, that's not what I meant. What I meant is that in the first case the source of the rock's motion is to a certain extent intrinsic to itself, while in the second case the rock's motion is because it is moved extrinsically. "A rock falls because Earth's gravity attracts it" - this is true, and it is just my point. The Earth attracts the rock because of something in the rock, something which makes the rock inclined to move towards the Earth, i.e. its mass. Nothing has to be added to make the rock fall except the properties of the rock and its environment, its near proximity to the Earth. But to make the rock fly upward some extra force has to be added from outside. Whether this tendency of the rock to move towards the Earth rather than away from it is explained in terms of Aristotelian "natural resting places" or Newtonian forces is, I think, irrelevant to this point. The point is that the natural properties of the rock incline it go towards the Earth (or whatever the nearest massive body is), while something outside the rock is required to overcome this natural attraction and go away from the nearest gravity well.

Dr Torley continues:

(2) Sullivan supposes that a process as simple as passing a spark through goo could generate life. To Aristotle, this would have seemed plausible; but in the light of what we now know, it is scientifically incredible.


I did not suppose this. I was and am in principle agnostic as to whether this is possible in theory. I believe I said that I doubt that it is possible, but if one believed otherwise the thing to do is to try and see. If detailed empirical investigations have shown that passing a spark through goo cannot generate life, then that's that. If the question is "what are the laws of nature and what are they capable of?" the thing to do is to observe nature.

Over at Siris it was recently suggested that Cartesianism may be more sympathetic to ID than other forms of scholasticism. This seems penetrating to me, partly because it strikes me that there may be a similarity in ID to the way Descartes' scientific speculation dictated the laws of nature, and what they could and could not accomplish in the corporeal realm, from a priori considerations.

A bit later Dr Torley suggests that Dr Feser and I are in disagreement about immanent causality, but I think Dr Feser has explained here that there's no real disagreement on this point. He then repeats his definition "A living thing is a thing with a good of its own," and says "I hope Sullivan would agree with this finalistic definition of life." I've already mentioned my hesitations about this definition, however, so I won't repeat them.

About natural substances, Dr Torley writes:

At the same time, though, I do think it is rather odd to speak of raindrops, lakes and mountains as “natural substances”, as Sullivan does. For none of these things exhibits “an innate tendency to sustain itself in being” which Sullivan considers to be the hallmark of a natural substance. If a take a raindrop on a leaf and shake it, it may divide in two. If I want to scoop a cup of water from a lake, all I have to do is lower my cup into the lake and then take it out. And I can cart a whole mountain away, shovelful by shovelful, if I have an army of workers to help me.

A crystal, on the other hand, is another matter; according to chemists, it is really a giant molecule, so I’d be happy to call that a substance. A rock I’m not so sure about.


Earlier I wrote a little about this. It seems to me that it's not always easy to say exactly the degree to which a thing is one and therefore a substance, even if it is correct to call a thing substantial. It seems to me that raindrops, lakes, and mountains are each one, but to different degrees, and so are more and less substantial. My feeling is that a raindrop is less substantial than a lake, and a lake less substantial than a mountain. But teasing out these distinctions is matter for a different discussion.

I'm not sure that the fragility of nonliving natural things, the fact that they can be easily destroyed, is relevant to the substantiality. The lake acts in a lakelike fashion, which is different than how a river or a droplet acts, and to that extent has its own form and is one in a different way. The fact that it can be drained doesn't change that. On the other hand, to allude to a question asked by commenter David on earlier post, there is no "lake-and-a-rock-on-the-moon"-like fashion of acting. The mind can bring them together in thought, but in themselves there is no unity between them at all, as opposed to the properties that the lake as a whole, singular thing.

And I'm very unsure about the claim that a crystal is a substance while a mere rock is not. It seems very odd to me to say that because the parts of a diamond have more internal order therefore the diamond is a substance and lump of coal is - what? Not a substance, anyway. Furthermore, this position seems to imply that the lake is not a substance in summer when it's liquid, but when it crystallizes into an ice block in the winter it is a substance, which seems wrong to me.

Later Dr Torley writes:

I must say that I am somewhat perplexed by Sullivan’s claim (which echoes a similar claim by Professor Feser) that ID proponents conflate the question of what a thing is with the question of how a thing came to be. This, it seems to me, is precisely the mistake made by ID critics, including some who are of an Aristotelian persuasion. For instance, some Thomistic critics of ID have maintained that because the parts of a living thing have a natural tendency to be together, they must have had a natural tendency to come together, when the first bacterial cell came into existence. This is a complete non sequitur.


I do agree that this is a non sequitur. I make no claim whatsoever about whether there are natural laws explaining how the first living thing came to be. As I've said, this is a matter for empirical enquiry. What I do say is that I am not sure that one can tell, from the properties of a presently-existing organism, either that such laws of nature exist or that they do not. Dr Torley wants to insist that one can.

However, the point at issue here is: how was the first living thing produced? No-one has ever observed a living thing being produced from non-living matter. All observation to date supports the conclusion that this cannot happen. As far as we know, abiogenesis is scientifically impossible.


As I've said before, if there are no natural laws which can explain how life arose, then that's that. But I don't think it's such an easy step to go from "there is no scientific explanation for the origin of life" to "a living thing is an artifact with a recipe containing semantic content", etc.

At this point I don't think I have anything to add to the rest of Dr Torley's post beyond what I've said in previous entries. I am glad that he, Dr Dembski, Dr Feser, and others began this discussion. It's been very thought-provoking for me, and the fact that Dr Torley has been willing to engage with me as a novice has given me the opportunity to begin to think some of the issues out, for which I'm very grateful.

22 comments:

Burl said...

Michael

As I recall, Dr. Torley brought up Scotus to make the point that his understanding of our intelligence and God's being different in degree only was very supportive of ID. He felt that Scotus' theology was amenable to ID as opposed to Aquinas' understanding that the two 'intelligences' were completely different in kind and only analogous one to the other.

Thus, for Scotus and IDers, to find signs of what we see as intelligence in humans could be parlayed into statements about God's intelligence. For Aquinas, you are talking apples (artifacts) and oranges (organisms) that at best are merely similar in some limited way.

I am not clear where you are addressing this in your post.

Michael Sullivan said...

Burl,

I'm not addressing your point in this post, because Dr Torley never brought the Scotus connection back up after his initial post and my response to that.

My answer to his claim was, essentially, that while it is correct that Scotus holds that intelligence is a pure perfection which in a certainly way can be univocally predicated of both finite and infinite intelligences, still this is not relevant to ID's claims. Dr Feser's critiques of ID were on the grounds of the distinction between natural and artificial substances, not the difference between analogous and univocal predication, and I think that Scotus would hold a similar distinction and apply it similarly.

penman@truegosp.org said...

I personally believe that life did not come into existence naturally, but was supernaturally designed and created. Having said that, it may be impossible for science to determine if some kind of life COULD arise naturally given sufficient time, unless science can actually do it in the laboratory. And if science were ever to do that, I am sure that the kind of life produced would be so simple compared to the kind of life we see today, that there would be little comparison, and it would still leave open the question of whether the kind of DNA based life we see today could arise through natural forces. Any kind of life produced in the laboratory would probably not be much more than a relatively simple, self-replicating molecule, far less complex than DNA or any cell.

The key question would be, can natural forces produce an arrangement of atoms that would form a self-replicating molecule or collection of molecules. I believe it is the physical organization and arrangement of atoms, along with the natural chemical processes that occur when the right arrangement is produced in the presence of the right molecular motion (heat) that makes a physical thing alive. Once you have the right atoms combined to form the right molecules, and the right collection of molecules in the right physical arrangement to reproduce the collection, you have physical life. It would be difficult to rule out that such an arrangement could occur naturally through random events even if science fails to do it in the laboratory.

But science really doesn't try to prove if such life could come into existence naturally. As I point out in my website on creation, science assumes that life came into existence through natural causes because the scientific method does not allow consideration of any other causes but natural causes. From the point of view of science following the scientific method, the existence of life is sufficient evidence that life came into existence from non-living matter through natural, random processes only.

David said...

"What I meant is that in the first case the source of the rock's motion is to a certain extent intrinsic to itself, while in the second case the rock's motion is because it is moved extrinsically."

What's the difference? Don't the laws of physics boil down to a catalogue of intrinsic properties (mass, charge, etc.)? Certainly whether the rock is falling down or thrown up, it is acted upon by an external force (the earth's gravitational force, or the force of a hand/etc.). In either case, the rock reacts the way it does because of what is in the rock, in co-operation with something extrinsic.

I can't say this is a peril of Aristotelian science, though; in fact, it actually follows from it. Newton can be seen as a refinement of Aristotle (just as Einstein in turn refined Newton). The same principle still applies: a Newtonian body still has a "natural resting place", it's just that instead of that natural place being "the centre of the cosmos", it turns out to be "where it already is". (Not that it seems particularly relevant to ID questions; but it is interesting to note that modern science has wholeheartedly embraced an Aristotelian notion of final causality — it just refuses to call it by that name!)

Burl said...

(Not that it seems particularly relevant to ID questions; but it is interesting to note that modern science has wholeheartedly embraced an Aristotelian notion of final causality — it just refuses to call it by that name!)

This is extreme;y relevant to the whole current argument over medieval metaphysics vs science debate.

Burl said...

Dr. Sullivan,

I have read and reread the posts of yourself, Dr. Feser, and Dr. Torley, as well as many of the commenters. I am not convinced that your assessment here is as focused as it might be:

"My answer to his claim was, essentially, that while it is correct that Scotus holds that intelligence is a pure perfection which in a certainly way can be univocally predicated of both finite and infinite intelligences, still this is not relevant to ID's claims. Dr Feser's critiques of ID were on the grounds of the distinction between natural and artificial substances, not the difference between analogous and univocal predication, and I think that Scotus would hold a similar distinction and apply it similarly."

I do agree with your post conclusions that this is an empirical matter that scientific methods of reasoning are well equipped to deal with.

Michael Sullivan said...

David,

What's the difference? Don't the laws of physics boil down to a catalogue of intrinsic properties (mass, charge, etc.)?

Perhaps there's no difference from the point of view of mathematical physics, which is not concerned with the concepts of nature or substance, and for which there is no difference between natural and artificial, intrinsic and extrinsic; but there is a difference for natural philosophy.

Burl:

I am not convinced that your assessment here is as focused as it might be:

You may well be right, but your criticism is not specific enough for me to know what to do with it.

I do agree with your post conclusions that this is an empirical matter that scientific methods of reasoning are well equipped to deal with.

I wonder if you've misunderstood. What I claimed was a matter for empirical inquiry was whether life could arise through the laws of nature; not whether there was a relevant distinction between natural and artificial substances. We don't know that cars are artifacts and trees are not simply because we see cars being built and trees growing, but also for other reasons, which I won't go into again.

Burl said...

Dr. Sullivan

I guess I am still unclear on how (and where in your posts) you came to the conclusion in this

"My answer to his claim was, essentially, that while it is correct that Scotus holds that intelligence is a pure perfection which in a certainly way can be univocally predicated of both finite and infinite intelligences, still this is not relevant to ID's claims.”

Dr. Torley emphasized Soctus' univocal intelligence, as is most evidently from his blog post titled “In Praise of Subtly”, with a picture of Scotus and the lead paragraph

“You might not know the guy in the picture above. John Duns Scotus, O.F.M, was one of the greatest theologians of the Middle Ages. A penetrating thinker of unsurpassed ingenuity, he was nicknamed the Subtle Doctor. Later on in this post, I’ll argue that in one particular respect, his philosophy is particularly ID-friendly – even more so than that of St. Thomas Aquinas. “

And when he gets to Scotus later in the post, he explains why Scotus is so relevant for ID and important in the whole intelligence evident in the design of artifact/organism discussion.

Part 1

Burl said...

Part 2

“Do ID proponents worship a different God from the God of classical theism?
Professor Feser faults ID on theological grounds as well. He seems to be convinced that ID proponents are theological disciples of William Paley. He also claims that ID proponents are tied to an anthropomorphic conception of God, regarding Him as nothing more than a Great Architect, rather like the Masons did in the 18th century. In particular, he faults ID proponents for applying terms like “intelligent” to God in the same way (i.e. in a univocal sense) as they are applied to human beings. In his post, The trouble with William Paley (November 4, 2009), he explains why he objects to this way of talking about God:
Paley and Co. conceptualize this designer on the model of human tinkerers, attributing our characteristics (intelligence, power, etc.) to him in a univocal rather than an analogous way (to allude to a crucial Thomistic distinction explained in a previous post). To be sure, “design arguments” also emphasize that the differences between human artifacts and the universe indicate that the designer’s power and intelligence must be far vaster than ours. But we are necessarily left with a designer conceived of in anthropomorphic terms – essentially a human being, or at least a Cartesian immaterial substance, with the limitations abstracted away.
Thus for Feser, ID’s theological flaw is that its conception of the Designer is ananthropomorphic one, because it applies the concept of ‘design’ in a univocal sense to both human designers and the Designer of the cosmos and life.
Four brief comments in reply:
(1) ID proponents do tend to apply terms “intelligence” and “design” to the Designer and to human beings alike, in a univocal sense, as I’ll show below by quoting from the writings of Professors William Dembski and Jonathan Wells, and from K. D. Kalinsky.
(2) Thomists might object to this, but they can’t speak for everyone. For instance, the Catholic theologian Duns Scotus (whose portrait is at the top of this post) taught that the term “intelligent” had the same meaning when applied to God and human beings. I should add that St. Thomas Aquinas and Duns Scotus were not so far apart on this issue, anyway.
(3) Professor Feser has got ID proponents pegged wrong. We’re not Paleyites. He’d be more charitable if he called us Scotists.
(4) ID proponents do not maintain, and have never maintained, that God creates things in the same way as an artificer makes an artifact. ID says nothing about how the Designer makes things, period.
Let me explain. One of the philosophical differences between St. Thomas Aquinas and Duns Scotus was that for Aquinas, all affirmative talk about God is analogicalat best, whereas for Scotus, some of the positive terms we apply to God (e.g. “intelligent”) are true in the same sense that they are true for us.
Thus for Aquinas, the statement, “God is intelligent” simply means “There issomething in God which is to God like intelligence is to humans.” Putting it mathematically,
X: God = Intelligence: Human beings.
Likewise, the statement, “God is loving” means “There is something in God which is to God like love is to loving parents.” This is what Aquinas calls real analogy of proportionality.
Additionally, God is the cause of knowledge and love in humans, where the causal relationship is an intrinsic one, which brings about a similarity in the effect (intrinsic analogy of attribution). A good explanation of Aquinas’ views on analogy can be found at http://members.optusnet.com.au/~gjmoses/relang2a.htm .

Burl said...

Part 3

"For Scotus, this isn’t good enough. Saying that X is to God what intelligence is to a human being tells me nothing about X, if I don’t already know what God is. Also, there’s no point in saying that my intelligence is like God’s if I don’t know what “like” means. Scotus held that since intelligence and goodness were pure perfections, not limited by their very nature to a finite mode of realization, they could be predicated univocally of God and human beings. To be sure, God’s way of knowing and loving is altogether different from ours: it belongs to God’s very essence to know and love perfectly, whereas we can only know and love by participating in God’s knowledge and love. Also, God’s knowledge and goodness are essentially infinite, while our knowledge and goodness are finite. However, what it means for God to know and love is exactly the same as what it means for human beings to know and love. As Dr. Thomas Williams puts it in his article on Duns Scotus in The Stanford Encyclopedia of Philosophy :
The doctrine of univocity rests in part on the claim that “[t]he difference between God and creatures, at least with regard to God’s possession of the pure perfections, is ultimately one of degree” (Cross [1999], 39)… If we are to follow Anselm in ascribing to God every pure perfection, we have to affirm that we are ascribing to God the very same thing that we ascribe to creatures: God has it infinitely, creatures in a limited way. One could hardly ask for a more harmonious cooperation between ontology (what God is) and semantics (how we can think and talk about him).
I should add that the Catholic Church has never condemned Duns Scotus’ views. AsThe Catholic Encyclopedia notes in its article on Scotism, there have even been bishops, cardinals, popes, and saints who were followers of Duns Scotus’ philosophy.
Leading ID thinkers do tend to treat intelligence as a pure perfection, which may be predicated univocally of God and humans (as Duns Scotus taught). On the charge of univocal predication, we gladly plead guilty. On the charge ofanthropomorphism, however, we plead not guilty. Here, for instance, is how Professors William Dembski and Jonathan Wells define “intelligent design,” “intelligence” and “design” in their book, “The Design of Life,” 2008, Foundation for Thought and Ethics, Dallas (page 3):

Burl said...

Part 4

"Intelligent Design. The study of patterns in nature that are best explained as the product of intelligence.
Intelligence. Any cause, agent, or process that achieves and end or goal by employing suitable means or instruments.
Design. An event, object, or structure that an intelligence brought about by matching means to ends.
On page 315, Dembski and Wells define intelligence in more detail, as “A type of cause, process or principle that is able to find, select, adapt, and implement the means needed to effectively bring about ends (or achieve goals or realize purposes). Because intelligence is about matching means to ends, it is inherently teleological.”
In other words, intelligence is manifested by agents that are capable of adapting means to ends. I have to ask: where’s the anthropomorphism here? I can’t see any. I believe St. Thomas himself would have approved of this definition, as he writes in his Fifth Way: “Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer.”
Duns Scotus distinguished God’s intelligence from ours on the grounds that God’s is essentially infinite, while ours is finite. In a similar vein, ID proponent K. D. Kalinsky writes in his online article, “Intelligent Design Required by Biological Life”:
Our observations indicate that there does not seem to be any known limit to the amount of functional information that intelligence can produce. It seems to be capable of producing anywhere from 0 bits and up.
The underlying idea here is that an intelligent enough Designer can create any effect, no matter how complex. That does not mean that the difference between God and humans is merely one of degree; it simply means that the term “intelligent” hasthe same meaning when predicated of God and ourselves, notwithstanding the infinite disparity between God’s intellectual capacities and ours, and the utter dissimilarity between the way God thinks and the way we do.”

In some of your comments, you imply that Torley hardly brought Scotus up in the discussion. He clearly did in a BIG way. Univocal intelligence was Torley's reason to place a keen focus on Scotus, but you do not seem to think so.

I think you did not focus on Torley's main point of interest in Scotus. And I do not understand why.

Michael Sullivan said...

Burl,

I really don't think it was necessary to cut and paste so much of Dr Torley's post. Obviously, since I responded to him in detail, I read it.

I'm not sure if I can say any more clearly what I've already said. If brief: I don't hold to Dr Feser's views on analogy, and so I wouldn't criticize ID from that standpoint. Nor did I. So ID is compatible with Scotism to the extent that it is possible to speak of intelligence in creatures and in God in a univocal sense. But - and this was the whole point of my part of the discussion - I'm not sure that this helps Dr Torley, since I believe a Scotist would take issue with ID on other grounds, including Dr Feser's non-analogical objections. I explained some of this in a comment on Dr Feser's blog here: https://www.blogger.com/comment.g?blogID=8954608646904080796&postID=8155277367584049157.

My point is that Dr Torley can appeal to Scotus for univocity all he wants and still have problems grappling with conceptions of nature which will be common to most Aristotelians. If God wrote a book, created a car, or inscribed tablets, or whatever, we could recognize them as composed and designed, just as human artifacts, by a univocal conception of intelligence. The point at issue however is whether natural things are like that. On the other hand, one could very well make a metaphysical argument to God's intelligence from the intelligibility of the natural world and the laws of nature in general, but that's not what Dr Torley is doing.

It also seems to me that some of Dr Torley's formulations remain open to accusations that he makes God a divine tinkerer, a demiurge or craftsman within the world, rather than a transcendent cause outside of it. But again, I feel as though I've explained this already.

Burl said...

Thanks

It seemed to me that Torley wanted to show that ID could be a source of revelation of the classical theistic creator God via Scotus' view on intelligence, so that ID did not only lead to Paley's more recent God-view.

Best to you.

PS, Can you say what your doctorate is in, and what you do occupationally? I'll understand if you cannot.

Michael Sullivan said...

Burl,

It seemed to me that Torley wanted to show that ID could be a source of revelation of the classical theistic creator God

I don't think this is right. The ID people seem to insist that their inference to intelligence is indifferent with respect to whether the designer is an alien, demiurge, transcendent creator, etc. If their arguments succeed all they can tell is that someone intelligent designed life, but not whether that intelligence is this-worldly or other-worldly.

My doctorate is or will be philosophy - I'm graduating in a week and half. At this point I don't have an academic position, although I have taught courses at a couple of universities. Right now my main occupations are raising my two children and studying. My wife is a psychiatrist, and that's what pays the bills.

Burl said...

We are both right! I think Dr. Torley's sensibilities are to find common ground between what ID finds and what classical theists attribute to God; however, the ID methodology is, as you say, agnostic on who the designer is, and thus what - other than intelligence - can be predicated.

eric said...

Dr. Sullivan (responding to David regarding rocks, gravity, throwing): "Perhaps there's no difference from the point of view of mathematical physics, which is not concerned with the concepts of nature or substance, and for which there is no difference between natural and artificial, intrinsic and extrinsic; but there is a difference for natural philosophy."

There might be room to reconsider whether there is even a difference for natural philosophy.

When a force acts to push a rock, the force (like gravity) is external and is also interacting (as with gravity) with the intrinsic mass of the rock. Consider intertia.

I question whether natural philosophy would require the distinction that gravity pulling is fundamentally different from magnetism pulling or some other natural force pushing. Push interacts with mass, just as pull must.

In all these cases, "the source of the rock's motion is to a certain extent intrinsic to itself" or rather, is necessarily connected with properties intrinsic to itself. It is not more intrinsic in the case of gravity than the others. The others likewise interact with the same intrinsic properties.

Likewise, in all these cases, including gravity, it is simultaneously true that "the rock's motion is because it is moved extrinsically", to use your terms.

eric said...

p.s. How much of our ancient intuitions, e.g. regarding rock movement, have been misled by the bias of our eyes, i.e what we can or cannot see?

The earth is clearly external to the falling rock, at least as much as a club or a volcano, and in some senses far more so. (The whole of the earth's mass is acting to attract the falling rock, not merely the spot nearest the rock.)

Yet we do not see the earth moving (even though it is) or acting upon the rock, and we don't see the earth's gravity at all, even though it would be real and present, even if the rock were not. They are extrinsic to the rock, but not seen as influencing the movement of the rock.

The natural and understandable ancient intuition is then to attribute falling exclusively to the intrinsic properties of the rock itself -- the one thing that we do see moving.

Yet, the appearance that the falling rock is not being acted upon by extrinsic influences is an illusion of our eyes. I would question whether that case is essentially different from a visible volcano ejecting a rock or a bat striking a ball or a visible magnet attracting or repulsing an object.

Do you still "see" any essential difference? ;-)

Michael Sullivan said...

I question whether natural philosophy would require the distinction that gravity pulling is fundamentally different from magnetism pulling or some other natural force pushing. Push interacts with mass, just as pull must.

Eric,

my understanding of Einsteinian physics is that gravity is not correctly thought of as pulling. Same with magnetism. The behavior of a heavy body in a gravity well or a charged body in an electromagnetic field should not be understood as simple billiard-ball type interactions. There is a fundamental difference between the mutual attraction between two massy or charged bodies on the one hand and a body pushing or pulling by the application of force through direct contact on the other. In the first case the falling rock or attracted magnet cooperates in its own motion; in the second case it merely submits to it.

I wonder if this sufficiently answers your objections.

eric said...

Dr. Sullivan, thanks for the reply. I quite agree that my description was not technically accurate. It was intentionally simplified (but hopefully not too simplified for the purpose). For example, yes, gravitation is mutual. However, in the case of the earth and a falling rock, obviously the mass of the earth is the dominant or major contribution by far, even though the mass of the rock participates.

All that said, no I don't think those additional details change the main point. You had seemed to want to say that the falling of the rock was intrinsic and not extrinsic, in a manner that distinguished it from other forces interacting with the rock.

My point (and I think David's) was to question this distinction. The earth and its contribution to the gravity well are clearly extrinsic to the rock. As I proposed in my last post above, I suspect that our ancient intuitions that specially associate falling with only intrinsic properties of the rock may have been misled by reliance on what we can see (which does not include the extrinsic role of the earth).

Meanwhile, I would suggest that other forces also necessarily interact with the intrinsic properties of an object. Imagine playing baseball, but substituting a similarly sized cannonball. I think it would quickly become plain that throwing and hitting it requires interaction with its intrinsic properties.

eric said...

p.s. Dr Sullivan: "In the first case the falling rock or attracted magnet cooperates in its own motion; in the second case it merely submits to it."

To more directly engage your statement, I would question the use of "merely submits".

If you mean to say that "merely submits" means something like "does not participate in the interaction" I would suggest that is not true. Consider inertia (mentioned earlier) and the baseball vs. cannonball example I just gave.

A body in motion tends to stay in motion. A body at rest tends to stay at rest.

Either way, in both cases, the intrinsic properties of the body do participate in determining the motion of the body.

[On the other hand, when you say "cooperates", I wondered in passing if you might trying to draw a fine distinction between a participation that "cooperates" vs. a participation in determining its motion that "resists" or something like that. But I suspect not.]

Michael Sullivan said...

You had seemed to want to say that the falling of the rock was intrinsic and not extrinsic, in a manner that distinguished it from other forces interacting with the rock.

What I want to say is that the earth does not "act on" the baseball in just the same sense that the baseball bat acts on it.

Meanwhile, I would suggest that other forces also necessarily interact with the intrinsic properties of an object. Imagine playing baseball, but substituting a similarly sized cannonball. I think it would quickly become plain that throwing and hitting it requires interaction with its intrinsic properties.

While this is certainly true, I don't think it's helpful to think in terms of forces in this situation. Physics as the science of interacting forces just doesn't have anything to say about substance in the way I've been talking about it. But for natural philosophy it is not the case that every body and its motion is reducible to its mathematical description.

As for your other comments, I would suggest that there is a distinction between the sine qua non of a motion and actually contributing to the motion. As you point out, the mass and density of the baseball are integral to the possibility of the bat's moving it the way that it does, and a body with different mass and density would not be moved in the same way under a similar action. But that is not to say that the ball is a cooperating efficient cause in its motion upward, the way that it is such a cause in its motion downward. The kinetic energy whereby the ball goes up is supplied from the bat from without; otherwise the ball would never go up. Nothing is put in the ball to make it fall down. It falls because of what is in it by nature and because of its proximity to the earth. But the earth doesn't add energy to the ball to make it fall.

I don't see how inertia is relevant here. The question is about the origin, the efficient cause, of the motion, not about the motion once it has been produced.

eric said...

I think I may be catching onto your point, and so changing my view. But first this reply...

Dr. Sullivan: "I don't see how inertia is relevant here. The question is about the origin, the efficient cause, of the motion, not about the motion once it has been produced."

Inertia isn't only about how a body stays in motion, once it is in motion. It also pertains to its inherent/intrinsic tendency for a body at rest to remain at rest -- unless acted upon by an outside force (e.g. the bat, gravity, magnetism).

Even when acted upon by some force, including for gravity, the mass resists motion. The gravitational force between the earth and the rock is mutual, but that does not mean they equally move, due to the earth's far greater mass and inertia. With two equally massive bodies, that would not be so.
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Despite all that, your interest, as I understand it now, is in what contributes positively to the motion, not how it might be resisted or changed or affected in other ways.

If that is the exclusive focus for your point (not more generally about what total factors determine the net nature of the motion), then I see that each object's mass does contribute to the mutual gravitational attraction in a way that is different from the bat hitting it.

I would still observe that this relationship is not in its nature intrinsic to the rock in isolation. You cannot find this by looking only at the rock and its own properties.

To put it another way, the old picture that the earth is just "there" and the rock's properties alone are doing the "falling" is still simply a misleading illusion.

If you want to say "the earth doesn't add energy to the ball to make it fall", I'm not sure how a physicist would prefer to express the fine point. Yet, I would say it is plain that the contribution of both the earth and the rock are necessary, and of the two, the contribution of the rock to the gravitational force is nearly negligible compared to that of the earth. Though we might not say it is "putting energy into the rock", nevertheless the earth is primarily responsible for the movement, far more than the rock. (For example, set the same rock in space similarly distant from a space station or other body will far less mass. The falling motion is not the same.)

In short, the "falling" in terms of contribution would have far more to do with the properties of the earth than of the rock. The word "down" tells us more about what is outside of the rock and extrinsic to it than it does about what is inside of the rock and intrinsic to it.

But ultimately, it is mutual and I now agree that the rock does contribute toward the "falling" motion due to its own properties in a way that is different from being hit by a bat.