How Aquinas confuses the First and Second way

[balto]

If you do not accept that the heel of the golfer’s club begins to accelerate at the exact same microsecond as he accelerates the handle then there is nothing more to be said here.

I believe anyone who passed their final year of Physcis at secondary school will accept Aquinas’s stick example as demonstrating “simultaneous causality.”

If you accept both the above then I suggest you have an understanding of “simultaneous”
that escapes me.

Is our disagreement really a disagreement over semantics? If you don’t like the term “simultaneous causality” then you are welcome to suggest another term and we can use that one instead. But what I described is really all we are talking about. You seem to be making this more complicated than it needs to be. I think that one day you are going to be thinking about this problem and then out of the blue something will click and you’ll say to yourself “oh, that’s all they are talking about? Well everyone knows that’s true.” It’s happened to me more than once concerning certain Thomistic doctrines.

You were on the right track in your analysis based on “frozen” moments in time.
When you freeze the causal chain it becomes clear that at that instant in time the current moving effect has not been caused by the current moving cause … but by the moving cause of a preceeding instant.

That cannot be the case. If that were the case, then the rock is currently changing for no reason, because the cause started at a certain time but had no effect until a later time. At that frozen instant, you are saying that the cause of the rock’s change was at a prior instant, so at this frozen instant there is nothing causing the change. Rocks do not accelerate by nature, so there must be an external reason for its being changed, but your analysis makes it the case that there can be no reason at all for this.

 

[utunumsint]

First, Aquinas clearly contradicts himself when he says “what is moved by violence is not moved by itself… If it is moved through itself, then it is moved either violently or by nature.”

Hey thinkandmull,

I took a close look at Balto’s post 21 and 22. I think he is right here. Let me break down paragraph 8 in SCG and let me know if this helps clarify things:

Principle to be proved -

[8] In the second way, Aristotle proves the proposition by induction [Physics VIII, 4].

What he is refering to here is this:** “namely, that everything that is moved is moved by another…”**

Now, before getting into the proof itself, he establishes the following key points, which he will then bring into his proof.

Point 1-

Whatever is moved by accident is not moved by itself, since it is moved upon the motion of another.

Point 2-

So, too, as is evident, what is moved by violence is not moved by itself.

Point 3-

Nor are those beings moved by themselves that are moved by their nature as being moved from within;

The next few clauses are further examples of point 3.

• Point 3.1 -

such is the case with animals, which evidently are moved by the soul.

• Point 3.2-

Nor, again, is this true of those beings, such as heavy and light bodies, which are moved through nature. For such beings are moved by the generating cause and the cause removing impediments.

Given the above points, he moves on to prove the principle that that everything that is moved is moved by another,

Now, whatever is moved is moved through itself or by accident [Point 1]. If it is moved through itself, then it is moved either violently [Point 2] or by nature; if by nature, then either through itself, as the animal, or not through itself, as heavy and light bodies.[Point 3 with example 3.1 and 3.2]

Now, he could have started this proof better because the way he states it seems to contradict point 2, but he goes on to bring in point 2 and 3, which he has just defined, right after making this statement. He clearly thinks that given the definitions he has provided in points 1, 2, and 3, the conclusion obviously follows as such:

Therefore, everything that is moved is moved by another.

So he is not contradicting himself. He is using the points he has just established in his final proof. If you want to prove the proof wrong, then you have to dispute his points 1, 2, or 3.

God bless,
Ut

 

[utunumsint]

This is not the problem UUS.
Of course all presently observed motion had to have an efficient cause to kick it off (ie an acceleration).

The more subtle difficulty is whether or not the constant motion we now observe (after the object has been launched) requires a concurrent sustaining cause. Newton said it doesn’t, Aristotle said it did, even in space.

Do you still disagree?
If so provide an example and analyse it in detail according to Newton/Aristotle’s principles so we can discuss.
Ut

Newton clearly did think it needed a sustaining cause, as I have said. He blamed it on God (occasionalism). The reason why is because his law is merely descriptive in nature. It does not and cannot explain the why. I believe we have the answer now in quantum mechanics, which is what I was trying to point out in my posts below. If I am right, then, of course, I have only pushed back the problem to quantum mechanics, which is a different discussion.

God bless,
Ut

 

[Richca]

This is not the problem UUS.
Of course all presently observed motion had to have an efficient cause to kick it off (ie an acceleration).

The more subtle difficulty is whether or not the constant motion we now observe (after the object has been launched) requires a concurrent sustaining cause. Newton said it doesn’t, Aristotle said it did, even in space.

Do you still disagree?
If so provide an example and analyse it in detail according to Newton/Aristotle’s principles so we can discuss.
Ut

I think it is a misunderstanding of Newton’s first law of motion or the law of inertia that an object once set in motion requires no concurrent sustaning cause. The law of inertia simply does not address whether it has a sustaining cause or not (is there not at least a sustaining force applied to the object by the mover such as in projectile motions?)
or whether there is a mover of some sort which insures that an object obeys the first law and which is in that sense responsible for its motion. As James Weisheipl says: “In Newtonian physics, there is no question of a cause, but only of differential equations which are consistent and useful in describing phenomena.”

Now, we know from the metaphysics of St Thomas Aquinas which is verified with certainty from divine revelation, Holy Scripture, and the Catholic faith that an object such as the moon and its motion and orbit around the earth has a metaphysical sustaining cause which is none other than the First Mover and First Cause, God, as the CCC#308 says:
"The truth that God is at work in all the actions of his creatures is inseparable from faith in God the Creator. God is the first cause who operates in and through secondary causes: “For God is at work in you, both to will and to work for his good pleasure.” Far from diminishing the creature’s dignity, this truth enhances it. Drawn from nothingness by God’s power, wisdom and goodness, it can do nothing if it is cut off from its origin, for “without a Creator the creature vanishes.”

Further, the CCC#300 says:
"But because he is the free and sovereign Creator, the first cause of all that exists, God is present to his creatures’ inmost being: “In him we live and move and have our being.” In the words of St. Augustine, God is “higher than my highest and more inward than my innermost self”.
As St Thomas Aquinas explains, God is the first cause of our life, our moving, and our being, indeed, of all creatures whether animate or inanimate and not just in some distant past but in the here and now.
The CCC#301 states further:
“With creation, God does not abandon his creatures to themselves. He not only gives them being and existence, but also, and at every moment, upholds and sustains them in being, enables them to act and brings them to their final end…“How would anything have endured, if you had not willed it? Or how would anything not called forth by you have been preserved?” (Wisdom 11:25).”

Newton’s first law of motion does not nullify Aquinas’ first proof for the existence of God based on the obvious fact of motion or change in the world. If we think it does, then I think
we probably don’t understand what Aquinas is saying and possibly what Newton is also saying.I think Aquinas is not just interested in local motion, but the metaphysics of motion or change which involves change of anykind whatever, change as a being of some kind which he says following Aristotle is nothing else than the reduction of something from potentiality to actuality. Aristotle used the concepts of potency and act in order to explain the reality of motion and change which had puzzled earlier greek philosophers who either denied the reality of change saying it is an illusion or who said change is the only reality.

Granted that Newton’s first law of motion used in conjunction with mathematics has probably been useful in describing planatary orbits and such, how do you test whether this law can be proven? Are there any inanimate bodies in the universe not affected by external forces of some kind or other such as gravity or electromagnetism especially if we view this in light of Newton’s other law of universal gravitation?
Secondly, for Aristotle and Aquinas, motion is an imperfect act, an incompleted act, it is for the sake of some end; for every agent acts for an end. Supposing therefore, that a inanimate body is set in motion without ever being affected by any external forces, according to Newton’s law, it would stay in motion indefinitely; a motion for the sake of motion without any end, purpose, or completion, in a word, without a final cause. Thirdly, I believe Aristotle says that it is not possible for a body to stay in a rectilinear motion indefinitely. I have not studied the reasons he gives for this, but I believe he does say this.

It is unmistakable that the earth and the moon for example are in motion. In our experience of the world, the only things that move themselves locally
are animals with souls; inanimate things do not move themselves.
We would probably not consider the earth and moon to be living things such as animals yet they are moving. The question then arises, what is moving them or causing their motion?

 

[Blue_Horizon]

Is our disagreement really a disagreement over semantics? .

It really just comes down to accurate observation of local motion and the inferential consequences that follow.

Yes or no, do you accept that:

…the heel of the golfer’s club begins to accelerate at the exact same microsecond as he accelerates the handle?

 

[Blue_Horizon]

The more subtle difficulty is whether or not the constant motion we now observe (after the object has been launched) requires a concurrent sustaining cause. Newton said it doesn’t…"

If it is clear please provide an authoritative source on Newton (or his own words) for your opinion?

I suggest you have misinterpreted whatever you have read on the matter because Newton’s First law of Motion clearly states that constant velocity does not need to be explained by any sustaining efficient force whatsoever.

Rather it is only a change in that uniformity (ie acceleration) that necessitates this explanation of an outside force. As Newton’s First Law puts it:
“an object … continues to move at a constant velocity unless acted upon by an external force”
I believe you are confusing ontological causality here with the efficient cause of local motion (force).

 

[Blue_Horizon]

I think it is a misunderstanding of Newton’s first law of motion or the law of inertia that an object once set in motion requires no concurrent sustaning cause. The law of inertia simply does not address whether it has a sustaining cause or not (is there not at least a sustaining force applied to the object by the mover such as in projectile motions?)

Richca I don’t think Physics is your strong point because you may not be aware of the seminal difference between velocity and acceleration in this discussion.
Projectile motion is clearly not relevant to this discussion point because it does not involve constant velocity.
The change in place that is caused by constant velocity in space (where there is no air resistance) does not need to be explained by any outside applied sustaining force whatsoever. That is exactly what Newton’s First law is all about.

Sure, we need an outside force to explain how an object goes from 0 to 50kmh in the first place.
But once it is at 50kmh that outside force is no longer involved in the ongoing change of place which constant velocity represents.

To this extent we have sustained motion without a concurrent sustaining outside force or cause. I am saying no more or no less than this.
Why is it objectionable?

 

[utunumsint]

If it is clear please provide an authoritative source on Newton (or his own words) for your opinion?

I suggest you have misinterpreted whatever you have read on the matter because Newton’s First law of Motion clearly states that constant velocity does not need to be explained by any sustaining efficient force whatsoever.

Rather it is only a change in that uniformity (ie acceleration) that necessitates this explanation of an outside force. As Newton’s First Law puts it:
“an object … continues to move at a constant velocity unless acted upon by an external force”
I believe you are confusing ontological causality here with the efficient cause of local motion (force).

Have you read Newton’s Principia?

God bless,
Ut

 

[Richca]

Richca I don’t think Physics is your strong point because you may not be aware of the seminal difference between velocity and acceleration in this discussion.
Projectile motion is clearly not relevant to this discussion point because it does not involve constant velocity.
The change in place that is caused by constant velocity in space (where there is no air resistance) does not need to be explained by any outside applied sustaining force whatsoever. That is exactly what Newton’s First law is all about.

Sure, we need an outside force to explain how an object goes from 0 to 50kmh in the first place.
But once it is at 50kmh that outside force is no longer involved in the ongoing change of place which constant velocity represents.

To this extent we have sustained motion without a concurrent sustaining outside force or cause. I am saying no more or no less than this.
Why is it objectionable?

No created thing can either exist or move without the universal causality of God. Secondly, a moving body without a cause is inexplicable.

 

[Blue_Horizon]

Secondly, a moving body without a cause is inexplicable.

Richca I am not able to continue discussing this point with you because you are too vague when it comes to specifics and you seem to hold to philosophic principles about local motion that, apparently, cannot ever be falsified by accurately observed examples of local motion.

Sure, the existence of a body that also happens to be in motion needs an efficient cause, but the motion itself - not always. If the world can always have existed then why not uniform motion?

Rather than admit that your principles of local motion may be in need of minor correction you seem to be saying that there is nothing new that modern day Physicists can tell you about observed reality.

I am reminded of Galileo and the bishop he invited to look through his telescope at the moons of Jupiter. The bishop allegedly replied along the lines of “I don’t need to look through your blurred and distorted lenses to know that such a thing is impossible by the Catholic faith and is no more than a figment of your desiring imagination.”

No created thing can either exist or move without the universal causality of God.

Noone is denying that. But your credal assertion here is so generalised, vague and ambiguous as to be meaningless in this discussion about the causality of local motion.
So we have come back full circle to begging the question that this thread started with - namely the confusing of the five ways into one confusing tangle of different causal explanations that need to be separated out and treated each on its own merits not tangled together and treated as one.

 

[Blue_Horizon]

Have you read Newton’s Principia?

God bless,
Ut

UUS I am challenging you to provide something more weighty than your own opinions and interpretations of Newton as the newton you see is not the Newton I see.

I have provided you clear, precise and authentic statements from Newton countering your interpretation of him.

If you cannot provide similar objective material from Newton when asked then your credibility for your interpretation of Newton will be zero .

Its your call.

 

[Linusthe2nd]

It looks like we cannot take this any further if you do not accept that Aristotle and Aquinas consider change of place a perfectly valid form of motion/change that necessitates an efficient cause. That’s just a fact as far as I can see and the First Way as an aposteriori proof based on all types of motion stands or falls on the total applicability of that principle. That is what a principle is - a universal truth that must hold in all cases. Only one counter example is required to disprove its validity - and Newton found one…uniform motion in a straight line.

I discussed Newton’s uniform motion in my thread " The First Way Explained, " ( you will have to searh for it.). Newton explained in several places, especially in Optics, that the cause of this phenomenon was likely God. In that case, God would be the efficient cause. Thomas often makes the point that God is the ultimate efficient cause for every motion and change. It should be noted that there is no perfect vacuum, certainly not in space, and not even in the laboratory. Strictly speaking, Newton is performing a " thought experiment " based on extrapolation, so was Galileo.

Aristotle’s concept of efficient cause applied only to the sublunar, lower world whose motions and changes were caused by the Celestial Sphere above it but did not extend to God, who was strictly an final cause. For Thomas, God was both an efficient and final cause.

But there is another principle of motion and change for Aristotle and that is nature.
John A. Weisheiple, in Nature and Motion in the Middle Ages, discusses Newton’s principle of uniform motion at great length. From his discussion it is easy to see that the theoretical uniform motion is either caused by the nature of the moving object, which was caused by God as the efficient cause, or by God directly as the efficient cause. Of course Newton was speaking of the movement of heavenly bodies. In a paper not included in this book he discusses the motion of objects in space, but I haven’t got hold of this paper yet - but some day maybe I will take the time to go to a local library that has it.

As far as projecticles on earth are concerned, Weisheiple concludes that the projector imparts an impetus which alters the nature of the projecticle so that it will continue moving naturally. The efficient cause is the agent imparting the impetus which alters the nature of the moving object or God, who gave the object a nature which could be changed in this manner. It is important to keep in mind that for both Aristotle and Thomas, nature or form is never an efficient cause.

You may have missed something…the **chain **of causality is not simultaneous.
The wood at the hand end of the stick moves before the wood at the bottom of the stick.
The stick can be considered a large number of small bits of wood “glued” to the next forming a long chain all the way to the bottom. Movement ripples down to the bottom over a short but definite duration of time as the hand accelerates. That is why the foot of a golf club always lags the handle and the club in fact bows backwards.

Since the power of the agent is applied to the stick, the power of the agent is simultaneous through the action of the stick. I think this is what Thomas is saying. He is illustrating a principle which holds true for all changes which are against nature or violent.

Linus2nd

 

[utunumsint]

I discussed Newton’s uniform motion in my thread " The First Way Explained, " ( you will have to searh for it.). Newton explained in several places, especially in Optics, that the cause of this phenomenon was likely God. In that case, God would be the efficient cause. Thomas often makes the point that God is the ultimate efficient cause for every motion and change. It should be noted that there is no perfect vacuum, certainly not in space, and not even in the laboratory. Strictly speaking, Newton is performing a " thought experiment " based on extrapolation, so was Galileo.

Aristotle’s concept of efficient cause applied only to the sublunar, lower world whose motions and changes were caused by the Celestial Sphere above it but did not extend to God, who was strictly an final cause. For Thomas, God was both an efficient and final cause.

But there is another principle of motion and change for Aristotle and that is nature.
John A. Weisheiple, in Nature and Motion in the Middle Ages, discusses Newton’s principle of uniform motion at great length. From his discussion it is easy to see that the theoretical uniform motion is either caused by the nature of the moving object, which was caused by God as the efficient cause, or by God directly as the efficient cause. Of course Newton was speaking of the movement of heavenly bodies. In a paper not included in this book he discusses the motion of objects in space, but I haven’t got hold of this paper yet - but some day maybe I will take the time to go to a local library that has it.

As far as projecticles on earth are concerned, Weisheiple concludes that the projector imparts an impetus which alters the nature of the projecticle so that it will continue moving naturally. The efficient cause is the agent imparting the impetus which alters the nature of the moving object or God, who gave the object a nature which could be changed in this manner. It is important to keep in mind that for both Aristotle and Thomas, nature or form is never an efficient cause.

Since the power of the agent is applied to the stick, the power of the agent is simultaneous through the action of the stick. I think this is what Thomas is saying. He is illustrating a principle which holds true for all changes which are against nature or violent.

Linus2nd

Right. Thanks for posting this Linus. “But there is another principle of motion and change for Aristotle and that is nature.” This is what I was trying to demonstrate with Blue Horizon about the underlying quantum mechanics that makes classical physics possible. Blue Horizon dismissed this idea as confusing ontological causation with efficient causation. But it does prove the point that everything that is moved is moved by another. In this case, the cause of locomotion is the nature imparted to objects by God which allows such motion. God is the efficient cause. He is the efficient cause of the underlying quantum structure of nature that makes such motion possible.

As the article I posted mentions:

In this article we show that quantum mechanics actually explains why Newton’s laws of motion are good enough to predict how footballs and satellites move. For Newton, fundamental laws had to be axioms—starting points. For us, Newton’s laws are seen to be consequences of the fundamental way the quantum world works.

Does that make sense to you Linus?

God bless,
Ut

 

[balto]

It really just comes down to accurate observation of local motion and the inferential consequences that follow.

The “inferential consequences that follow” are precisely what seems to be in dispute here. One of the inferential consequences that follow was mentioned right here:
"balto:

That cannot be the case. If that were the case, then the rock is currently changing for no reason, because the cause started at a certain time but had no effect until a later time. At that frozen instant, you are saying that the cause of the rock’s change was at a prior instant, so at this frozen instant there is nothing causing the change. Rocks do not accelerate by nature, so there must be an external reason for its being changed, but your analysis makes it the case that there can be no reason at all for this.

I noticed that you tried to evade responding to this.

Yes or no, do you accept that:

Yes, the atoms that the hand accelerates are simultaneously accelerated. The other atoms are not directly acted on in the first instant so they are not accelerated until other atoms accelerate them. What is so difficult/controversial about all of this? You keep appealing to Newton and/or physics to try to evade the metaphysical issues that are really what this discussion is about.

 

[Linusthe2nd]

Right. Thanks for posting this Linus. “But there is another principle of motion and change for Aristotle and that is nature.” This is what I was trying to demonstrate with Blue Horizon about the underlying quantum mechanics that makes classical physics possible. Blue Horizon dismissed this idea as confusing ontological causation with efficient causation. But it does prove the point that everything that is moved is moved by another. In this case, the cause of locomotion is the nature imparted to objects by God which allows such motion. God is the efficient cause. He is the efficient cause of the underlying quantum structure of nature that makes such motion possible.

As the article I posted mentions:

Does that make sense to you Linus?

God bless,
Ut

I did mention nature as the cause of motion and change in those things which have a nature. Yes, that is very important. Many commentators on both Aristotle and Thomas over look this important principle.

It is for you brains to discuss Quanrtum Mechanics, I understand nothing about about it. That always gets me in hot water. All I will say is that it is the primary nature of a thing that determines its natural activity, it is not its ultimate composing atomic particles. It is human nature which directs the activity of his composing physical particles, not visa versa.

Linus2d

 

[utunumsint]

I did mention nature as the cause of motion and change in those things which have a nature. Yes, that is very important. Many commentators on both Aristotle and Thomas over look this important principle.

It is for you brains to discuss Quanrtum Mechanics, I understand nothing about about it. That always gets me in hot water. All I will say is that it is the primary nature of a thing that determines its natural activity, it is not its ultimate composing atomic particles. It is human nature which directs the activity of his composing physical particles, not visa versa.

Linus2d

Agreed. However, our natural activity would not be possible without the underlying classical and quantum physics that governs physical particles, right? They enable natural causal powers - at least when it comes to locomotion.

Also, I am wondering if you could clarify what you mean here?

As far as projectiles on earth are concerned, Weisheiple concludes that the projector imparts an impetus which alters the nature of the projecticle so that it will continue moving naturally. The efficient cause is the agent imparting the impetus which alters the nature of the moving object or God, who gave the object a nature which could be changed in this manner. It is important to keep in mind that for both Aristotle and Thomas, nature or form is never an efficient cause.

Just so I understand, the agent also has a nature, which includes causal powers. Are not the causal powers of the agent considered an efficient cause? I think, yes, right? I suppose your point is that the alteration of the thing moved by the initial agent is its nature, and the nature which is altered (either by changing its velocity or by its sustained motion) is not an efficient cause of its own motion at that point? It is simply doing what its altered nature says it will do?

God bless,
Ut

 

[Linusthe2nd]

Agreed. However, our natural activity would not be possible without the underlying classical and quantum physics that governs physical particles, right? They enable natural causal powers - at least when it comes to locomotion.

Of course the ultimate physical particles operate according to their natural properties but not so as to be independent of the form or nature of the being of which they are the constituent physical parts. I would compare the controling and guiding nature of the form to the causality of God as compared to the secondary causality of natural beings. The form directs all the being’s activity, including that of the underlying physical particles, but not so as to deprive the physical particles of their own proper activity. Clear as mud, right. But I don’t see how we can say more.

Also, I am wondering if you could clarify what you mean here?

Just so I understand, the agent also has a nature, which includes causal powers. Are not the causal powers of the agent considered an efficient cause? I think, yes, right? I suppose your point is that the alteration of the thing moved by the initial agent is its nature, and the nature which is altered (either by changing its velocity or by its sustained motion) is not an efficient cause of its own motion at that point? It is simply doing what its altered nature says it will do?

God bless,
Ut

I think when we speak of the agent cause we are also speaking of its causal powers. I don’t recall either Aristotle or Thomas separating the two. But it is actually the causal power of the agent cause which is transferred to all the secondary causes, so that when we reach the last secondary cause, it is the causal power of the agent cause which is simultaneous to the activity fo the moved or changed object.

Yes, it is the nature of the agent cause which is the efficient cause of the moved being. So if we are speaking of a projectile, the effect is the transfer of an impetus to the moved object so that the nature of the moved object is modified so that its velocity continues under the power of its modified nature until changed by an opposing force.

And if we are considering Newton’s constant fixed velocity of an object in a " vacuum " then one of three things has happened. Either the nature of the moving object is such that it maintains a constant velocity. In which case God is the efficient cause, since he is the creator of such a nature. Or God is the direct efficient cause of such constant velocity. Or the efficient cause is the collection of causes which constructed the moving object and projected it, through and applied impetus. And even in this case God is the First Agent Cause.

Weisheipl’s book is fascinating if you care to read it. Check with World Cat to find it in a library near by. I bought it for $150 and that was after a month of looking. It was the most expensive single book I ever bought - but I read it in the library first, so I knew it was worth while.

Linus2nd

 

[utunumsint]

Thanks for responding.

So let me look at the three possibilities you mention:

“And if we are considering Newton’s constant fixed velocity of an object in a " vacuum " then one of three things has happened:

1. 
   *]Either the nature of the moving object is such that it maintains a constant velocity. In which case God is the efficient cause, since he is the creator of such a nature.
   *]God is the direct efficient cause of such constant velocity.
   *]The efficient cause is the collection of causes which constructed the moving object and projected it, through and applied impetus. And even in this case God is the First Agent Cause.”
   
   I think 1 makes sense to me. I don’t like 2 since that smacks of occasionalism. I’m not sure I understand 3.
   
   1 seems to concur with my idea of enabling causality. In this case, locomotion is simply a property of matter. The cause of the initial change in velocity is due to the causal power of an agent (efficient causality), or an instrumental cause that terminates in the primary agent cause. The initial cause that brought the object to that constant state of velocity is still an efficient cause. But what keeps keeps the object in motion after the change in velocity is a part of the nature of physical objects.
   
   This reminds me of my post 82 where Aquinas says:
   

   Nor are those beings moved by themselves that are moved by their nature as being moved from within;

   He gives the following example:
   

   Nor, again, is this true of those beings, such as heavy and light bodies, which are moved through nature. For such beings are moved by the generating cause and the cause removing impediments.

   I think he is referring here to the idea that the four elements have a natural place where they tend (water in one place, earth in another, air in still another, fire tending upward). Here the motion is part of their nature, much like what we are proposing here for motion, only using modern physics.
   
   God bless,
   Ut

 

[Blue_Horizon]

Newton explained in several places, especially in Optics, that the cause of this phenomenon was likely God.

Just give us the quote please Linus and we will see if we are really comparing apples with apples and whether it can be reconciled with Newton’s 1st law which I have quoted.

But there is another principle of motion and change for Aristotle and that is nature… From his discussion it is easy to see that the theoretical uniform motion is either caused by the nature of the moving object, which was caused by God as the efficient cause, or by God directly as the efficient cause.

We are going over old ground here Linus - see post #32 and #41 below.

eg “Self movers” (ie how the soul of living things moves the body) is not an example of the “motion” Aquinas has in mind in the First Way (cf Magee) - this is the basis of the 2nd Way not the First Way."

Besides it seems there can be no chain of motion greater than two links when we call in the temporal self-mover link from temporal body to the “soul” of the self-mover. Maybe in Aristotle’s time, or even Aquinas’s, people would posit the Celestial Bodies were “alive” (which is what ‘self-mover’ usually implied) … but not nowadays. This seems a dead-end as Magee opines.

As far as projecticles on earth are concerned, Weisheiple concludes that the projector imparts an impetus which alters the nature of the projecticle so that it will continue moving naturally. The efficient cause is the agent imparting the impetus which alters the nature of the moving object or God, who gave the object a nature which could be changed in this manner.

Well with complicated Maths one can still say that the geocentric model of the Solar System still holds too. But for my money Galileo and Kepler are simpler because they do not have to also account for a misplaced religio/metaphysical ideology.

Likewise with projectiles I’ll go with Newton, inertia, energy-transfer and simplicity - as Ocham suggests we should do in both cases.

Since the powerof the agent is applied to the stick, the power of the agent is simultaneous through the action of the stick. I think this is what Thomas is saying.

This is so ambiguous as to be of little assistance Linus.
Everything rests on what you mean by “power” which certainly doesn’t look like “a force applied over a certain distance for a certain time” which is how Newton thought of it (as does any boy who made it past age 15 at school).

If that is how we validly can define your unusual phrase then the agent’s “power” certainly is not available at the bottom of the stick the exact moment it is applied by the hand.

That does not deny a chain of causality from hand to ball - but lets not say its “simultaneous” for it isn’t, its only available after a time lag. That is what I call a sequential chain of local motion.

So it would seem that the ball cannot be put into act at the same time as the hand is put into act. If Aquinas calls that “simultaneous” then it seems he is poorly translated .

 

[Blue_Horizon]

Blue Horizon dismissed this idea as confusing ontological causation with efficient causation. But it does prove the point that everything that is moved is moved by another. In this case, the cause of locomotion is the nature imparted to objects by God which allows such motion. God is the efficient cause. He is the efficient cause of the underlying quantum structure of nature that makes such motion possible.
Ut

I don’t deny this UUS but what you are describing sounds to me like the material cause of local motion not the efficient cause.