How Aquinas confuses the First and Second way

[Blue_Horizon]

If you are talking about temporally-separated causes and effects, such as local motion, then that series can potentially be infinite.

I tend to agree with your proposition above.

Perhaps we have different understandings of cause/effect though?
I do not believe the cause/effect that operates in “sumultaneous chains of causality”
is the same as that which operates in “sequential chains of causality.”

For, by definition, all sensible chains of causality (which is afterall how Aquinas began his argument) are time-bound in every stage … yet Aquinas argues infinite regression is not possible.

If Aquinas is later talking about “simultaneous chains of causality” then his aposteriori starting point (local motion which is always time-bound and can therefore regress infinitely because such motion forms “sequential chains of causality”) doesn’t fit well.

A logician might say he is using terms equivocally and the logic consequently isn’t as tight as it could be.

I find it interesting that Gilson always maintained that the First Way has nothing to do with what we today call “the principle of causality.” I believe it is related o the above above difficulties.

Also related and interesting is that most people get the “whatever is moved is moved by another” wrong. Its highly ambiguous.
As Leo Elders points out… “Omne quid movetur, ab alio movetur” is poorly translated by the above English as the tenses are blurred.It is best rendered, “whatever is being moved (transitive) is being moved (passive) by another.”

Modern day causality sees cause/effect chains as completed at each intermediary link before the “ripple” continues (ie cause/effect-cause/effect-cause/effect).
The distinction you make between simultaneous and sequential attempts to distinguish these two world views.
Clearly Aquinas (who sees causality as primarily simultaneous in the Five Ways) does not see causality like we see it today.

Therefore we today do not really see eye to eye with Aquinas in his common sense aposteriori starting point about local motion and causality.
Even in simple examples of unchained motion we see efficient “causality” operating very differently, always temporal sequentiality, not simultaneously.

If this be the case I have to agree with Gilson.
In explaining the First Way (which may well be valid) maybe we need to avoid enlisting the concepts of “cause” and “effect.”
There is now little common ground of understanding there with Aquinas.
Unfortunately this leaves the First Way as not much clearer than hieroglyphics because we don’t seem to have words or intuitive common-sense explanation or readily understood real-world examples that well express the “causal” principle he is presenting.

Does the concept of “simultaneous causality” actually exist in today’s “sensible” Newtonian worldview (that’s a pun by the way).

 

[utunumsint]

Wouldn’t it be better to emphasize the idea of instrumental causation rather than simultaneity of the causation in a per se series? That way, the idea of time need to matter as much, although it still comes to play in explaining the actuality of the entire series.

edwardfeser.blogspot.ca/2010/08/edwards-on-infinite-causal-series.html

But it is arguably possible at least in theory for there to be a per se causal series in which some of the members were not simultaneous. Suppose a “time gate” of the sort described in Robert Heinlein’s story “By His Bootstraps” were possible. Suppose further that here in 2010 you take a stick and put it halfway through the time gate, while the other half comes out in 3010 and pushes a stone. The motion of the stone and the motion of the hand are not simultaneous – they are separated by 1000 years – but we still have a causal series ordered per se insofar as the former motion depends essentially on the latter motion. I am not saying that this really is possible, mind you; it presupposes that time travel itself is at least possible in principle, which is controversial at best. But let’s grant it for the sake of argument. Insofar as the hand’s operation and existence will themselves presuppose various other factors, we have a continuation to the regress of causes ordered per se which cannot be ended until we reach a purely actual uncaused cause. The end result is the same, even if the statement of the argument needs to be made more complicated.

God bless,
Ut

 

[Blue_Horizon]

You did say that, I apologize. But you’ve given me an impossible question to answer. Local motion is defined as essentially involving time (x = x0 + vt - 0.5at^2 if I am remembering my physics correctly), so how could there by an instance of local motion where no time passes?

Fair enough - that’s where I am at too re the First Way…scratching my head.
It looks like any 15yr old teenager who has half understood his Physics lessons will be forever well inoculated against understanding Aquinas’s First Way from that time forward.

Modern day scholastics play down the significance of our understanding of “inertia” (and hence the ubiquitous presence of time/duration in all sensible chains of cause/effect…which are hence always sequential) that Aquinas and Aristotle didn’t quite have…as if it make’s little difference to their principles. I think this is premature. The consequences seem more profound than this and more exploration needs to be done.

For example:
By “motion” Aquinas clearly regarded the principles involved as next to self-evident even in local motion. I believe he (and Aristotle) were understandably mistaken in the allegedly intuitive examples they provided (eg hand/stick/ball).

What appears sensibly self-evident is not always so - even today we know that concrete walls are in fact not very solid at all, they are mostly empty space. Likewise Newton will not allow us to accept that hand/stick/ball all move at the same instant that the hand accelerates - to do so would contradict Newton’s laws of motion, which is provable by experiment… The causality is not easily justified as simultaneous.

So we have no sensible reason to believe that any local motion in our world could ever be simultaneous. How then can we easily induct and accept that there is a principle of simultaneous causality based on observing movement (let alone other types of sensible change) - which is apparently the starting raw data of the First Way?

Aquinas and Local Motion:
It seems to me that Aquinas, by local motion, simply means a change of place. However he like Aristotle did not seem to differentiate the different ways in which a body can change place. It involves both velocity movement and acceleration movement but these did not seem to be the well differentiated, developed and defined concepts schoolboys understand readily today. And the difference is huge.

Acceleration movement always requires an outside cause (force) … Newton would agree with that.
But a constant velocity movement (in the absence of friction) does not require an outside force to be maintained.

So Aristotle was not in principle correct when he said “whatever is moving must be moved by another” if he was was talking about movement of a body at a constant velocity from place to place.

So here is a real-world example of an ongoing and incomplete accidental change (“where” is the 4th of the nine types of accidents of a substance) that has no ongoing efficient cause to explain it. I understand this to be anathema to Aristotle’s philosophic system of causality.

Is there any sense in which Aristotle/Aquinas could be correct by modern understandings of local motion? I think so, but its limited.

Clearly when speculating on local motion they were primarily thinking of the heavens and the celestial objects that moved eternally in circles. Thus Aristotle appears to have held they were “living” (gods?) because the only things that can move themselves are living things which are moved by a non-material principle (their soul).

Aquinas was ambivalent on this point. He suggested that if the Celestial Bodies/Spheres were not alive then per se causality must be ruled out in favour of an external mover - an angel, (or perhaps God directly if we are speaking of the highest Celestial Sphere which moves the other Celestial Spheres).

Regardless of this, Newton would agree that the motion of Celestial Spheres (maybe that is all) has to require a moving cause because they are in fact not at constant velocity. Yes, at constant speed, but not in a straight line. If an object at a constant speed changes its direction regularly it is in fact accelerating because velocity is a vector quantity (ie has direction as well as speed). The Celestial Bodies were known to orbit (or at least move in circles) which means their motion was in fact an acceleration not a constant velocity. Acceleration is always caused by the action of an external cause.

So Aristotle and Aquinas were correct in principle wrt the Celestial Spheres conforming to the principle “what is moving is moved by another”. However this principle does not hold in all cases of local motion - esp when the motion is constant speed in a straight line.

In conclusion understanding the First Way seems to run into difficulties for two reasons: Newton’s laws of motion and the temporal latency involved in all changes of place … both different aspects of “inertia.”

 

[Blue_Horizon]

Wouldn’t it be better to emphasize the idea of instrumental causation rather than simultaneity of the causation in a per se series? That way, the idea of time need to matter as much, although it still comes to play in explaining the actuality of the entire series.

edwardfeser.blogspot.ca/2010/08/edwards-on-infinite-causal-series.html

God bless,
Ut

Its interesting that Fezer says:

So, it is ultimately their instrumental character, and not their simultaneity, which makes every member of a per se ordered causal series other than the first depend necessarily on the first.

I don’t know if what he says is tenable or not but I agree with him that the “chain of causality” proposition cannot hold if we hold it must be simultaneous for the reasons outlined above.

But what is really meant by “their instrumental character” and can the alleged truth of this proposition flow from an argument based on sensible motion as in the First Way anyway?
Perhaps it will work in the other ways but the First Way, due to its aposteriori starting point does seem an extra hard nut to crack in this respect.

Anyhow its midnight and my head hurts.

 

[wittgenstein]

Aquinas doesn’t speak of just one motion moving in between the past and future, moving forward. He speaks of the impossibility of infinite intermediate motions. If motion could have been eternal, that would suffice to explain why there is present motion. There is no need to go from the horizontal to the vertical in speaking of motion alone; so the First Way would be worthless. Second Way doesn’t fit into motion theory, and neither do Leibniz’s arguments on things needing a sufficient reason for their existence. The Second way is correct, but the First Way disproves his theory of a rational eternal universe of motion

Does an infinite past explain anything? For example, by analogy, suppose the world is supported (sits on) an elephant and that elephant on an elephant…ad infinitum. Why are they elephants and not for example rocks?

 

[utunumsint]

Likewise Newton will not allow us to accept that hand/stick/ball all move at the same instant that the hand accelerates - to do so would contradict Newton’s laws of motion, which is provable by experiment… The causality is not easily justified as simultaneous.

From Ed Feser’s Scolastic Metaphysics "Newton’s law tells us that a body will continue its uniform rectilinear motion if it is moving at all, as long as external forces do not prevent this. It does not tell us why it will do so. In particular, it does not tell us one way or another whether there is a “mover” of some sort which ensures that an object obeys the first law, which is in a sense responsible for its motion…Aquinas’s principle and Netwon’s do not actually contradict one another. "

“Newton’s principle is concerned solely with local motion, change with respect to place or location. When Scholastic philosophers speak of “motion” they mean change of any kind… More to the point, for the Scholastic all such change involves the actualization of a potency. Hence what Aquinas’s principle is saying is that any potency that is being actualized is being actualized by something else (and in particular by something that is already actual). This principle is not in formal contradiction with Newton’s law of inertia because they are simply not talking about the same thing…and Newton’s law holds that external forces are required to move a thing out of this “state” and thus to bring about a change. But the Newtonian principle hardly conflicts with the Scholastic claim that “motion” - - that is to say, change – requires something to cause the change. The disagreement is at most over whether a particular phenomenon counts as a true change or “motion” in the relevant sense, not over whether it would require a mover or changer if it did so count.”

Perhaps the word motion is the cause of many of the problems. If we just stick with change, it wouldn’t be so confusing.

God bless,
Ut

 

[utunumsint]

Aquinas and Local Motion: It seems to me that Aquinas, by local motion, simply means a change of place.

It means any change whatsoever, as I understand Feser.

Acceleration movement always requires an outside cause (force) … Newton would agree with that.
But a constant velocity movement (in the absence of friction) does not require an outside force to be maintained.

Does he really say that, or simply describe this mathematically?

So Aristotle was not in principle correct when he said “whatever is moving must be moved by another” if he was was talking about movement of a body at a constant velocity from place to place.

If what Newton described was simply a mathematization of what actually happens, then this does not answer why this occurs.

I think this helps illustrate what he says later on in Scholastic Metaphysics.

Finally and most importantly, though, there is the point made in the previous section that physics simply does not give anything like an exhaustive description of nature in the first place, but abstracts from it everything that cannot be “mathematized” (to use Martin’s expression). This, as just indicated, includes the notion of act and potency, and thus causation as the Scholastic understand it. Newton’s law of motion reflects this tendency, insofar as they provide a mathematical description of motion suitable for predictive purposes without bothering about the origins of motion or the intrinsic nature of that which moves.

He also states in other parts of the book that the decoupling of cause and effect by Hume and those that came after him, are really at the root of what the issue is here. If efficient cause A is not intelligible apart from being the final cause of B, then A and B are not really separable in time, but constitute one event, not two events, even though there may be a gap in time between the cause and that being caused.

Its a good book. I’m having a good time reading through it. Although it is very technical.

God bless,
Ut

 

[utunumsint]

One last quote "It is important to emphasize however, that simultaneous does not entail instantaneous. An event is of course spread out through time. The point is that a cause’s producing its effect is part of the same one event in which the effect is being produced, however long this event lasts. "

 

[balto]

Aquinas and Local Motion:
It seems to me that Aquinas, by local motion, simply means a change of place. However he like Aristotle did not seem to differentiate the different ways in which a body can change place. It involves both velocity movement and acceleration movement but these did not seem to be the well differentiated, developed and defined concepts schoolboys understand readily today. And the difference is huge.

Acceleration movement always requires an outside cause (force) … Newton would agree with that.
But a constant velocity movement (in the absence of friction) does not require an outside force to be maintained.

So Aristotle was not in principle correct when he said “whatever is moving must be moved by another” if he was was talking about movement of a body at a constant velocity from place to place.

So here is a real-world example of an ongoing and incomplete accidental change (“where” is the 4th of the nine types of accidents of a substance) that has no ongoing efficient cause to explain it. I understand this to be anathema to Aristotle’s philosophic system of causality.

Is there any sense in which Aristotle/Aquinas could be correct by modern understandings of local motion? I think so, but its limited.

It seems to me that your objection to simultaneous causation rests on the fact that it is not sensible. That is a fair point to make I think, but human sensation occurs through time so if you define causation as being sensible then you are stuck with only temporal causation. But causation can be detected both sensitively and intellectually, so we can still know that simultaneous causation is real intellectually (if it were not real, there would be no way to make sense of temporal causation because causes and effects would be loose-and-separate as it were).

I think that utunumsint brings up a good point about the confusion between motion and change. When Aquinas talks about “motion” he is talking about what we understand by using the word “change.” To answer your Newtonian concerns, let’s suppose that there is an object moving at a constant velocity. Is it changing? No, not really. “Well isn’t it changing its position?” But that’s not an intrinsic change. I would think it is really just a Cambridge change because the object itself is not changing but its position relative to some other point is changing, but that is not a real relation.

But if a force acts on the object to accelerate it, then it is undergoing intrinsic change. At the moment the force acts on the object, the object experiences the force. It’s velocity may not have changed in this instant, but there is a difference between an object experiencing a force and one that isn’t, even if they have the same velocity. I don’t find that highly objectionable and that is all that Aquinas requires for simultaneous causation and the First Way. If causation is only temporal, then it would have to be the case that the force is acting on the object from [t1, t2] but the object does not experience the force until t3, but then why is the force acting on the object necessarily connected to the object accelerating if the force spends some amount of time not actually eliciting any effect in the object? What causes it to cause the effect at t3 when it wasn’t causing anything at [t1, t2] though it was acting on the object during this timespan?

 

[Blue_Horizon]

From Ed Feser’s Scolastic Metaphysics "Newton’s law tells us that a body will continue its uniform rectilinear motion if it is moving at all, as long as external forces do not prevent this. It does not tell us why it will do so.
In particular, it does not tell us one way or another whether there is a “mover” of some sort which ensures that an object obeys the first law…

This formulation of Newton’s view is a bit weird. It assumes that “rest” (or uniform velocity) needs to be explained. Its the other way around. A body only changes velocity if an external force acts on it. Uniform velocity does not need causal explaining, the “why” question only emerges with acceleration.

"Newton’s principle is concerned solely with local motion, change with respect to place or location. When Scholastic philosophers speak of “motion” they mean change of any kind… "

This seems very poor logic.
If a global principle of change is consistant and valid it must hold for all types of change of which local motion is one - as Aquinas asserts in the First Way. Indeed its his aposteriori basis for the arguments that follow. So if Aquinas cannot explain a single problematic with local motion change then the whole change principle fails.

Now there definitely is a problem with local motion.
Local motion is a change in the accidental property of material substances known as “where” (the 4th accidental property).

Aquinas clearly holds that a change cannot continue unless an external efficient cause is constantly acting. When the change ceases only then does the external cause cease to act. Now a body at a constant uniform speed is continuously changing its place isn’t it?
So according to Aquinas there must be an external cause acting. What is it?

Well Newton says there isn’t one and I agree. Aquinas was wrong on this type of change.
Therefore his whole principle of change falls over.
There are specific examples of motion without any cause at all. QED.

This principle is not in formal contradiction with Newton’s law of inertia because they are simply not talking about the same thing…

I think it is in contradiction. Local motion is an example of accidental change isn’t it?
So its a valid example of motion, so its an example of potency changing to act.

I realise its not an example of substantial change.
I realise its not an example of Creatio ex nihilo.

Bit it IS a type of motion change.
And it is a valid if minor example of movement from potency to act.

 

[Blue_Horizon]

One last quote "It is important to emphasize however, that simultaneous does not entail instantaneous. An event is of course spread out through time. The point is that a cause’s producing its effect is part of the same one event in which the effect is being produced, however long this event lasts. "

The problem is that chains of this type of causality don’t seem to exist exist in the temporal world.

In the sensible world a chain of causality always appears to be a series of completed events. The next “event” in the causal chain won’t begin until the prior one is completed. Indeed, it is the start of the next event that declares the preceding causal event has closed and done its “knock on” job.

Maybe this means we simply have an essentially different understanding of “cause” and effect" from medieval times even though we “see” the same sensible examples .

 

[Blue_Horizon]

But causation can be detected both sensitively and intellectually, so we can still know that simultaneous causation is real intellectually…

It may be better to say that causality is inferred from sensible observations heavily involving inductive reasoning.

(if it were not real, there would be no way to make sense of temporal causation because causes and effects would be loose-and-separate as it were).

We need to stay on topic, the context is the First Way based on motion of which the prime sensible observation is the** local **motion of the Celestial spheres.
In any case if a principle inducted from observations of local motion actually seem to fail when applied back to some types of local motion better observed/understood today then how can the principle be validly extrapolated to even more abstract forms of “motion”?

I think that utunumsint brings up a good point about the confusion between motion and change.

Local motion is indeed a valid example of “motion”, even to Aristotle. There is a problematic whether we like it or not.

When Aquinas talks about “motion” he is talking about what we understand by using the word “change.” To answer your Newtonian concerns, let’s suppose that there is an object moving at a constant velocity. Is it changing? No, not really. “Well isn’t it changing its position?” But that’s not an intrinsic change. I would think it is really just a Cambridge change because the object itself is not changing but its position relative to some other point is changing, but that is not a real relation.

I believe we would be completely mistaken if we believed Aquinas and Aristotle would agree with this. They clearly accept that local motion (accidental change) is an excellent example and intuitive example of all types of motion/change - especially the more abstract types of change such as substantial change (you seem to call this intrinsic change) or even Aquinas’s concept of potency/act (this is not always “motion” or “change” as it is a much bigger concept).
In the First Way (unmoved mover) both Aristotle and Aquinas were fairly clearly thinking of the local motion of the Celestial Spheres as a prime and valid example of all motion.

If you could find sources that clearly shows that Aristotle did not see his principle of causality applying to** local **motion (accidental change) I would agree with you. In fact it would be a breakthrough for me if you could .

But if a force acts on the object to accelerate it, then it is undergoing intrinsic change.
At the moment the force acts on the object, the object experiences the force. It’s velocity may not have changed in this instant, but there is a difference between an object experiencing a force and one that isn’t, even if they have the same velocity.

Yes, this is all very well and I tend to agree with you, but it isn’t actually what Aristotle or Aquinas say and it is inconsistent with their systems.
Any change whether accidental (local motion even if just constant speed) or substantial, it seems, requires an efficient cause according to both . Always.
Change due to acceleration is still “accidental” (ie not substantial or “intrinsic”) according to Aristotle and Aquinas - they made no distinction in local motion between velocity and acceleration in this regard. We have Newton to thank for that conceptual breakthrough.
That is why the First Way is now problematic.

If causation is only temporal,

I don’t know about that. Just saying that Aristotle’s/Aquinas’s principles wrt causality don’t actually work wrt local motion. In other words if they derived them from analysing examples of local motion then there was something wrong in their analysis.
Their principles of causality may work consistently in non temporal cases but how they came to those principles cannot be from observing real world examples of local motion.
This is why the First Way is problematic while the other cosmological arguments may not be.

then it would have to be the case that the force is acting on the object from [t1, t2] but the object does not experience the force until t3, but then why is the force acting on the object necessarily connected to the object accelerating if the force spends some amount of time not actually eliciting any effect in the object? What causes it to cause the effect at t3 when it wasn’t causing anything at [t1, t2] though it was acting on the object during this timespan?

Not sure that Newton would agree. Force always has an effect on matter by definition? Sure the object may not accelerate immediately…but to the extent it does not accelerate as a whole it must partially compress on the side receiving the force. Energy transfer is probably the key to this sort of analysis. Force is only known to act on an object because it transfers energy (and hence can be sensed). If energy is transferred by a force then there must be something that is moved some distance because E=Fd.
So the dis-place-ment will either be internal compression of the body or external movement of the whole body.
What sort of example are you thinking of?

 

[utunumsint]

The problem is that chains of this type of causality don’t seem to exist exist in the temporal world.

In the sensible world a chain of causality always appears to be a series of completed events. The next “event” in the causal chain won’t begin until the prior one is completed. Indeed, it is the start of the next event that declares the preceding causal event has closed and done its “knock on” job.

Maybe this means we simply have an essentially different understanding of “cause” and effect" from medieval times even though we “see” the same sensible examples .

Well yah! Exactly!

This is what Feser argues for at length in his books. That modern notions of causality are defective, deriving from enlightenment thinkers who rejected final and formal causation. If you try to understand Aquinas without first understanding the four causes, you will fail to appreciate what Aquinas and Aristotle were getting at.

I will write some more from Feser on per se sequences later on.

God bless,
Ut

 

[utunumsint]

The problem is that chains of this type of causality don’t seem to exist exist in the temporal world.

First from Feser’s account of how causation can be simultaneous:

…the standard Humean examples used to support the claim that a cause and its effect are essentially temporally separated are not convincing. For instance, to say that the motion of billiard ball A causes the later motion of billiard ball B is not quite right, for A’s motion could have been stopped before A had any causal influence on B, and B’s motion may or may not continue regardless of the continued presence of A. It is only at the point of impact that there is really any causation going on vis-a-vis A and B. But ball A’s impacting B and B’s being impacted by A are not temporally separated. They are just the same event. As we saw earlier, it is not quite right either to speak of the throwing of a brick causing the breaking of glass. It is rather the brick’s pushing into the glass this is the immediate cause and the glass’s giving way that is the effect, and these (unlike the trowing of the brick and the breaking of the glass) are not temporally separated but rather parts of one and the same event. Of course, the motion of billiard ball A and the throwing of the brick are causally relevant, and there is a perfectly legitimate sense in which we can speak of them as causes of the effects in question. But they are not the immediate causes of these effects, and immediate causes are always simultaneous with their effects.

So A and B in this instance is one and the same event. Now in a per se series, you have multiple events strung in a sequence where:

1. 
   *]B depends on A in A’s intrinsic act of causation. A son depends on a father for existence, but not in exercising his own causal powers. A stone moved by a stick, moved by a hand all derive their causality on the hand’s causal power. The hand is the principle cause of the motion of the stick and the stone. The stick is the instrumental cause. Note that in locomotion, the cause of any change in velocity has to be explained in a similar way. And the continued motion of an object after a causal change has occured also needs a causal explanation. You may say not, but I say yes. It is a property or power inherent in nature that allows this to happen. That power is causal and can be explained by further laws of physics. These laws explain the regularities observable in nature, and those regularities are enshrined as “laws of nature”. But then what is a law of nature? Simply a observed regularity? If this is so, then the term law of nature has no real meaning, since a regularity being a law of nature and a law of nature being an observed regularity is a circular argument. The Aristotelian appeals to causal powers inherent in the essences of things instead.
   *]The primal cause of the power has a higher or more perfect nature than the instrumental causes. The person who causes their hand to move has a higher nature than the stick or stone. A father begetting a son is not a causal series in this sense, because the father’s inherent power to beget a son is not the primal cause of the power of the son to beget his own son. That would just be weird.
   *]The cause and effect are simultaneous, but are not or need not be in an accidentally ordered series. The hand pushes the stick that pushes the stone. Of course these events happen through time as a process, and in other examples, that process make take an extended time. But the power that strings together all the instrumental causes has to continue to exist.
   
   God bless,
   Ut

 

[utunumsint]

I dug up this thread I posted back in Feb. forums.catholic-questions.org/showthread.php?t=859347 There are some interesting posts.

I remember quoting this from Fr. Benedict Ashley’s book:

For later Aristotelian the great puzzle was how to explain projectile motion. A ball obviously has no natural tendency to fly through the air, yet when struck with a bat moves until stopped. Aristotle himself tried to reconcile this obvious fact with the principle that “nothing moves itself” by supposing that when the ball is struck some force is communicates through the medium through which it moves, which then keeps it moving after it has left the bat that put it in motion. This seems to us absurd, be we should recall that today science still relies on the notion of “field”, that is, a medium, to explain the motion of bodies through that field. The Aristotelian commentators, beginning with John Philoponus (fl. sixth century CE), preferred, (rightly, in my opinion) to say that an impetus or force was imparted to the ball by the stroke of the bat. While they considered gravity to be a fundamental, natural force, a property of certain bodies, the impetus was a secondary type of force or active quality, accidental (preternatural) to the body that received it.
In this way, Newton’s later law of motion could be accounted for, since the impetus would keep the mall moving until stopped by another force. Moreover, since it was not strictly natural but secondary, it need not be predetermined to some specific result (final causality, teleonomy). To this explanation we can add that such an impetus is, as it were, “second nature” to the moving ball. Hence the impetus is not an efficient cause but a quasi-property, which can be eliminated from the body in a way that its true properties cannot. A heavy body remains heavy, even when another body stops its motion; but a ball will not start moving through the air without being again struck. Thus, as long as any force, whether strictly natural or imposed, can be traced back to fundamental physical, material forces (active qualities) that are natural, the argument for an immaterial Prime Mover still follows. As previously noted Newton realized this problem when he concluded that the gravitational force on which his whole system was built required that God as Prime Mover will its action.

God bless,
Ut

 

[utunumsint]

Interesting. In Feser’s Scholastic Metaphysics, he quotes from James Weisheipl’s Nature and Motion in the Middle Ages which seems to contradict the characterization of Aristotle’s position on impetus by Benedict Ashley’s from the previous post.

As James Weisheipl (1985) has shown, the idea that Aristotle and Aquinas held that no object can continue its local motion unless some mover is continuously conjoined to it is something of an urban legend. To be sure, this was the view of Averroes and of some Scholastics, but not of Aristotle himself or of St. Thomas. On the contrary, their view was that a body will itself tend to move toward its natural place by virtue of its form. That which generates the object and thus imparts its form to it can be said thereby to impart motion to it, but neither this generator nor anyting else need remain conjoined to the object as a mover after this generation occurs. (To be sure, the scientific details of their analysis – such as the supposition that the natural place of heavy objects is the center of the earth, and that projectile motion differes essentially from natural motions – are obsolete. The point is tht there is nothing in the Scholastic position that entails the crude “conjoined mover” model of causality often attributed to it.)

Looking back that the Benedict Ashley quote, he gets his information from Annaliese Maier’s On the Threshold of Exact Science (1982), essays 3, 4, and 5.

I might try to hunt these books down.

God bless,
Ut

 

[balto]

We need to stay on topic, the context is the First Way based on motion of which the prime sensible observation is the** local **motion of the Celestial spheres.
In any case if a principle inducted from observations of local motion actually seem to fail when applied back to some types of local motion better observed/understood today then how can the principle be validly extrapolated to even more abstract forms of “motion”?

Local motion is indeed a valid example of “motion”, even to Aristotle. There is a problematic whether we like it or not.

I believe we would be completely mistaken if we believed Aquinas and Aristotle would agree with this. They clearly accept that local motion (accidental change) is an excellent example and intuitive example of all types of motion/change - especially the more abstract types of change such as substantial change (you seem to call this intrinsic change) or even Aquinas’s concept of potency/act (this is not always “motion” or “change” as it is a much bigger concept).
In the First Way (unmoved mover) both Aristotle and Aquinas were fairly clearly thinking of the local motion of the Celestial Spheres as a prime and valid example of all motion.

If you could find sources that clearly shows that Aristotle did not see his principle of causality applying to** local **motion (accidental change) I would agree with you. In fact it would be a breakthrough for me if you could .

Well I think the issue is whether or not local motion is a valid type of change or not. I’m not sure what Aquinas and Aristotle thought about local motion, but they did not have as much scientific knowledge of the world as we have. I don’t think it is too problematic to fit this new knowledge into their metaphysical outlook. Maybe local motion is not a real change (like I argued earlier) but their notion that change as such requires a mover is still valid. Elsewhere when discussing the Fourth Way I believe that Aquinas uses an analogy where he says that fire is the principle or standard of heat. We know now that fire is not the standard of heat, but his basic point that if there are degrees of perfection then there is perfection full stop is still a valid insight. So I don’t think we need to get too hung up on Aristotle and Aquinas’ science.

Yes, this is all very well and I tend to agree with you, but it isn’t actually what Aristotle or Aquinas say and it is inconsistent with their systems.
Any change whether accidental (local motion even if just constant speed) or substantial, it seems, requires an efficient cause according to both . Always.
Change due to acceleration is still “accidental” (ie not substantial or “intrinsic”) according to Aristotle and Aquinas - they made no distinction in local motion between velocity and acceleration in this regard. We have Newton to thank for that conceptual breakthrough.
That is why the First Way is now problematic.

I don’t know that the difference between temporal and simultaneous causation is just the difference between accidental and substantial change respectively. I would hold that a force imparting net acceleration to an object involves simultaneous causation, but I don’t think that acceleration would involve a substantial change in the object. Local motion with zero acceleration would involve neither simultaneous causation nor substantial change.

Not sure that Newton would agree. Force always has an effect on matter by definition? Sure the object may not accelerate immediately…but to the extent it does not accelerate as a whole it must partially compress on the side receiving the force. Energy transfer is probably the key to this sort of analysis. Force is only known to act on an object because it transfers energy (and hence can be sensed). If energy is transferred by a force then there must be something that is moved some distance because E=Fd.
So the dis-place-ment will either be internal compression of the body or external movement of the whole body.
What sort of example are you thinking of?

Yes exactly, this is what I am trying to get you to see. Force having an effect on matter is all that is required for simultaneous causation and the First Way. When the force is acting on the object (cause), at the same moment the object is in some way experiencing the force (effect). That’s all you need for simultaneous causation I think. If there is only temporal cause-effect relationships, then this common sense viewpoint cannot be true. But we know it is true therefore there must be atemporal causation as well.

 

[Blue_Horizon]

Well I think the issue is whether or not local motion is a valid type of change or not. I’m not sure what Aquinas and Aristotle thought about local motion, but they did not have as much scientific knowledge of the world as we have. I don’t think it is too problematic to fit this new knowledge into their metaphysical outlook. Maybe local motion is not a real change (like I argued earlier) but their notion that change as such requires a mover is still valid. Elsewhere when discussing the Fourth Way I believe that Aquinas uses an analogy where he says that fire is the principle or standard of heat. We know now that fire is not the standard of heat, but his basic point that if there are degrees of perfection then there is perfection full stop is still a valid insight. So I don’t think we need to get too hung up on Aristotle and Aquinas’ science.

I don’t know that the difference between temporal and simultaneous causation is just the difference between accidental and substantial change respectively. I would hold that a force imparting net acceleration to an object involves simultaneous causation, but I don’t think that acceleration would involve a substantial change in the object. Local motion with zero acceleration would involve neither simultaneous causation nor substantial change.
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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.

Yes exactly, this is what I am trying to get you to see. Force having an effect on matter is all that is required for simultaneous causation and the First Way. When the force is acting on the object (cause), at the same moment the object is in some way experiencing the force (effect). That’s all you need for simultaneous causation I think. If there is only temporal cause-effect relationships, then this common sense viewpoint cannot be true. But we know it is true therefore there must be atemporal causation as well

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.

 

[Blue_Horizon]

Well yah! Exactly!

This is what Feser argues for at length in his books. That modern notions of causality are defective, deriving from enlightenment thinkers who rejected final and formal causation. If you try to understand Aquinas without first understanding the four causes, you will fail to appreciate what Aquinas and Aristotle were getting at.

I will write some more from Feser on per se sequences later on.

God bless,
Ut

I find binary alternatives a little unimaginative - don’t you?
Why can’t moderns have a better understanding of efficient causality than the ancients (who stand in need of some correction re alleged aposteriori arguments from local motion) and the ancients a better appreciation of the other three causes operating in the world that moderns tend to underestimate/ignore.

 

[Blue_Horizon]

Interesting. In Feser’s Scholastic Metaphysics, he quotes from James Weisheipl’s Nature and Motion in the Middle Ages which seems to contradict the characterization of Aristotle’s position on impetus by Benedict Ashley’s from the previous post.

Looking back that the Benedict Ashley quote, he gets his information from Annaliese Maier’s On the Threshold of Exact Science (1982), essays 3, 4, and 5.

I might try to hunt these books down.

God bless,
Ut

Yes that would be an interesting area to study further to better understand Aristotle’s thought. One has to be careful not to impose enlightenment prejudices (that all forces apparently acting at a distance must somehow act mechanically by contiguous contact of matter (whether heavy or volatile) onto Aristotle/Aquinas though).