I’ve thought about ways in which to apply these principles to the critique. I haven’t read the book, so I don’t have much beyond that. Vini might be interested, though.
I read this article not only due to personal interests but because I am doing a school project on the first way and wanted to respond to objections. I am newer to thomistic philosophy and so it is entirely possible I am just missing something, but how do per se causal series even exist in such a cases. The thing which sets say a ball into local motion in space does not need to persist in existence for the ball to keep on it's path. But say the ball encounters another ball which is still, and the first ball actualizes in the second ball the potential to move in a certain direction at a certain velocity, how would this be a per se causal series, because the ball which moves relies on nothing but its current state to actualize the potential and nothing else. I know this may sound like a very stupid objection and it probably is but I am new and am finding it difficult to reconcile this. Unless I am wrong in my thinking that the first way relies on per se causal series that must be simultaneous in every actualization. Again sorry if this is all over the place.
Thank you for this article. I heard about inertia objection long time ago but I didn’t know how to respond to it formally. I will be reading this piece again for shure.
Also while reading this article an analogy to De Ente occured to me. How a being can move (the principle of motion) and if it is moved (the act) those things are like essence and existence. So if the existence is always imparted to contingate being from outside the same would follow for the principle of motion. The motion is imparted from outside to the beings able to move.
This article sits squarely in my interest wheelhouse; I love it! I do have one question. Is there an issue with simply shifting the ontological baseline of 'no change' from a constant position (Δx = 0) to a constant velocity (Δv = 0)? Cause—in local motion—is then understood as force, shown as F=ma. An object at rest and an object of constant velocity both fit the criteria of a=0 (or Δv = 0) and thus need no active concurrent cause.
If the classic objection is that an object at point A has the potential to be at point B (and therefore requires a present mover to actualize that potency), I would argue that this begs the question of the ontological baseline. Position alone is an incomplete description of a state; we must know its velocity. If the object is at A and already possesses a constant velocity toward B, its arrival at B requires no new efficient cause (no additional force). The actualization of its journey to B already occurred when the object was initially accelerated. The transition from A to B is simply the relational unfolding of that prior actualization.
This is how I reconcile it, and I don't see how this would create a larger metaphysical issue. Please let me know if it does!
If position is the ontological baseline, I'd need some proof that we can actively actualize the location of the stationary object from A to B without acceleration. If you could demonstrate a causal mechanism for this—say, a hypothetical equation like ψ = f(m, v/Δx) that operates independently of Δv—then I would concede. But as I see it, and as is clearly evident to the senses, an actualization from stationary A to B only ever occurs with a change in velocity. Without a change in velocity, an active change in local motion cannot occur.
I'm not sure that this fits with Galilean relativity, one of the foundations of Newtonian Mechanics. It seems, rather, that your position implies absolute motion or a preferred reference frame.
This is a genuinely interesting objection — one that occurred to me many years ago when I was first studying Aristotelianism.
The objection may be formulated more precisely as follows. According to Aristotle, the potency involved in local motion must belong to the mobile itself: motion is “the actuality of the movable insofar as it is movable,” and Aristotle explicitly says that “motion is in the movable” (Physics III.2–3, 202a7–14). Yet suppose that a body has a constant non-zero velocity relative to an inertial frame (S). Relative to a second inertial frame (S'), moving alongside the body at the same velocity wrt S, that body is at rest. It may therefore seem that the body is actually moving according to one frame but not according to another. If motion is the actualisation of a potency intrinsic to the mobile, must there not be some privileged frame relative to which the body is either really moving or really at rest?
The objection, however, confuses the intrinsic potency of the mobile with the relational determination under which its motion is measured. The potency to undergo locomotion — to occupy other possible positions and enter into new spatial relations — is genuinely founded in the mobile. Nevertheless, the complete actuality signified by a determinate velocity is not a merely intrinsic, monadic property. It includes an order to another physical term: the body has such-and-such a velocity relative to a given ICS.
This distinction is entirely Aristotelian. Aristotle defines relatives (a category of being) as things whose character is expressed by reference to something else: “Those things are called relative” which are explained through their reference to another (Categories 7, 6a36–b1). He also observes that “the same thing may be small in comparison with one thing, and great in comparison with another” (Categories 6). The same subject may therefore simultaneously possess apparently opposed relational predicates, provided that they are predicated according to different termini.
For example, Socrates may actually be to Plato’s left while simultaneously being to Aristotle’s right. There is no contradiction, because he is not both to the left and not to the left of the same person. Similarly, Aquinas remarks that “a column is on the right of an animal, without change in itself, but by change in the animal” (Summa theologiae I, q. 13, a. 7). A relational denomination may thus vary without a corresponding intrinsic alteration in the subject denominated.
The same answer applies here. The body is not both moving and at rest secundum idem et ad idem. Rather, it is actually moving relative to (S) and actually at rest relative to (S'). Both relations are objectively true. The observer does not create the potency or the motion merely by observing it; the reference frame supplies the second physical term according to which the body’s velocity is determined.
Consequently, the Aristotelian doctrine requires that the potency and the actuality of motion be grounded in the mobile, but it does not require every quantitative determination of that motion to be an intrinsic property possessed independently of all relations.
Thus no absolute preferred inertial frame follows merely from the principles of act and potency and the Aristotelian notion of local motion. Aristotle’s own cosmology did contain privileged places, such as the centre of the cosmos and the natural places of the elements, but that is a further physical and cosmological thesis — not something demanded simply by the metaphysics of potency and act.
You say: “the reference frame supplies the second physical term according to which the body’s velocity is determined.”
But that isn’t what Galileo is claiming. He is claiming that the reference frame is that according to which the body’s velocity is actual. Hence, the motion of a body relative to some reference frame is not a “quantitative determination” of that motion. It is that very thing that makes it to be motion.
A body can only be said to be in motion with respect to a reference frame. Wagner wants to say that a body is being actualized irrespective of a reference frame. He can do that, but he breaks with modern physics.
First, a small correction: Wagner is not the author of the article — I am. Wagner explicitly says this in the prologue he wrote. I am also a Mathematics graduate and studied both Galilean mechanics and Special Relativity, so don’t worry, the issue here is not unfamiliarity with elementary kinematics — and contrary to what you said, I would never, ever claim that local motion is “actualised irrespective of a reference frame”.
In Galilean mechanics, a body may have velocity (v) relative to an ICS (S) and velocity (0) relative to another ICS (S'). But obviously the frame does not efficiently cause either state. It is simply the second term relative to which the body’s velocity is specified — every body has a relation (which is a category of being) to an ICS. The body’s velocity v is actual wrt to S and the body’s rest is actual wrt to S’ — there is no contradiction and Aristotle never claimed anything contrary to this. In fact, if you push this to the last consequences, you will note that Galilean mechanics only could refute the notion of “impetus” as an actual mover inside the body, which I prove in the article to be an incorrect reading of Aristotle — as such a mover would exist in the case of referential S and not exist in the case of referential S’!
The correct Aristotelian statement is that potency to motion belongs to the mobile in relation to an ICS, and the determinate predicate “moving at (v)” is therefore also relational (and yes, also actual, because a predicate being relational does not mean it is not actual).
If a body is moving relative to S and resting relative to S', it is not moving and resting in the same respect because the category of relation resolves such a problem. If Aristotle didn’t claim relation as a category, your criticism would be valid — but that is not the case. If a body is in uniform rectilinear motion wrt S, potency is being actualised in the subject even if the referential is only relative and even if wrt to S’ the body is at rest (it doesn’t matter). The force of the criticism which I refute in the article is precisely in the fact that I can pick any object in inertia and, relative to this object, I can pick an ICS with respect to which the body is in rectilinear motion and hence is having potency actualised relative to such an ICS. What is the mover of such motion according to the Aristotelian kinesiological axiom? This is what the article answers.
The mobile has the intrinsic capacity to enter into different spatial relations. Which velocity is predicated of it depends upon the chosen inertial frame. Nothing of this contradicts anything in the article — it only contradicts the positions refuted in it.
If you have studied relativity, how do you maintain presentism (with respect to Philosophy of Time)? This is the position of Ss. Augustine, Boethius, Anselm, Thomas, etc (following Aristotle), but is seemingly in direct conflict with SR. One can adopt a neo-Lorentzian interpretation, but that just stands flatly in contradiction to how science is performed, and so is a lacking response. I ask this because an act-potency analysis best stands when contextualized with presentism (though I think it can stand within eternalism), and so would be in opposition to modern science. Ontological pluralism is another concern, as well.
It’s possible that I’ve misread these statements of yours:
1) “every body has a relation (which is a category of being) to an ICS.”
2) “The correct Aristotelian statement is that potency to motion belongs to the mobile in relation to an ICS….”
If so, I apologize.
In the context of 1), you seem to be using ‘relation’ and ‘category of being’ to refer to Aristotelian concepts. But Aristotle would never say that every (or any) body has a relation to a reference frame. A reference frame is a mathematical artifact, a being of reason. Bodies don’t have real relations to beings of reason, though some beings of reason, when being known by a mind, have real relations to bodies.
For 2), I’m not sure what you mean by a potency “belonging” to a being, much less belonging in relation to something. A thing is potential or actual. Potentiality and actuality are not qualities or habits of being, much less relations. A relation is itself an actuality of the thing, and not a comparison that the mind makes between two things (a being of reason). So potency can’t belong to a mobile in relation to anything.
For Aristotle, motion has three terms: what is being moved, what it is moving from and what it is moving to. For local motion, the termini of the motion are places, like Ithaca and Athens. So a local motion is defined by a place in which the moved thing is actually and a place in which the moved thing is potentially. When the moved things’s place is fully actualized at the terminus ad quem, it then rests and the motion is complete. The telos of a motion is rest - the completion of motion - at a particular place. Nowhere in that account can you find an ICS. Nowhere in that account can you fit an ICS.
Aristotle’s understanding of motion clearly relies on ”some privileged frame relative to which the body is either really moving or really at rest:” the terminus a quo and the terminus ad quem, the two places which the moving body actually and potentially is, and thus the terms that define that very motion.
Second of all, going back to your first response. You seem to be confusing velocity and motion. Velocity and motion are not the same thing. Velocitas is a quality of a substance in motion; it is an effect in the moved by the mover (unde velocitas motus est effectus receptus a movente in aliquo habente magnitudinem, Commentary on Physics Theta, L. 21). Thus, it is something intrinsic to the body. And so that velocity is not founded on a relation to some other being, whether of reason or otherwise. (Now, that velocity can be in proportion to another velocity, but said proportion would itself be a being of reason, a quality in the mind of the knower.) Again, no room in the definition for a reference frame defined by a velocity.
None of this means that your defense of the first way fails, it just means that it denies a really important foundation of modern kinematics. Which is fine, but you have to account for that.
I read this article not only due to personal interests but because I am doing a school project on the first way and wanted to respond to objections. I am newer to thomistic philosophy and so it is entirely possible I am just missing something, but how do per se causal series even exist in such a cases. The thing which sets say a ball into local motion in space does not need to persist in existence for the ball to keep on it's path. But say the ball encounters another ball, which is still, and the first ball actualizes in the second ball the potential to move in a certain direction at a certain velocity, how would this be a per se casual series, because the ball which moves relies on nothing but its current state to actualize the potential and nothing else. I know this may sound like a very stupid objection and it probably is but I am new and am finding it difficult to reconcile this. Unless I am wrong in my thinking tha the first way relies on per se causal series thst must be simultaneous in every actualization. Again sorry if this is all over the place.
Great article! Have you thought of expending this into a critique of Schmidt's book against St Thomas arguments and existential inertia?
I’ve thought about ways in which to apply these principles to the critique. I haven’t read the book, so I don’t have much beyond that. Vini might be interested, though.
Crazy, I just found out about this yesterday and here is an article on this exact topic. Thanks Wagner.
Great article!
I read this article not only due to personal interests but because I am doing a school project on the first way and wanted to respond to objections. I am newer to thomistic philosophy and so it is entirely possible I am just missing something, but how do per se causal series even exist in such a cases. The thing which sets say a ball into local motion in space does not need to persist in existence for the ball to keep on it's path. But say the ball encounters another ball which is still, and the first ball actualizes in the second ball the potential to move in a certain direction at a certain velocity, how would this be a per se causal series, because the ball which moves relies on nothing but its current state to actualize the potential and nothing else. I know this may sound like a very stupid objection and it probably is but I am new and am finding it difficult to reconcile this. Unless I am wrong in my thinking that the first way relies on per se causal series that must be simultaneous in every actualization. Again sorry if this is all over the place.
Principal of sufficient reason is kinda of over reach of reason or to put it bluntly idolatry of reason. I love St. Thomas
Great article! So basically I was having difficulty due to crypto Averroists who call themselves thomist funny how that happened
Thank you for this article. I heard about inertia objection long time ago but I didn’t know how to respond to it formally. I will be reading this piece again for shure.
Also while reading this article an analogy to De Ente occured to me. How a being can move (the principle of motion) and if it is moved (the act) those things are like essence and existence. So if the existence is always imparted to contingate being from outside the same would follow for the principle of motion. The motion is imparted from outside to the beings able to move.
This article sits squarely in my interest wheelhouse; I love it! I do have one question. Is there an issue with simply shifting the ontological baseline of 'no change' from a constant position (Δx = 0) to a constant velocity (Δv = 0)? Cause—in local motion—is then understood as force, shown as F=ma. An object at rest and an object of constant velocity both fit the criteria of a=0 (or Δv = 0) and thus need no active concurrent cause.
If the classic objection is that an object at point A has the potential to be at point B (and therefore requires a present mover to actualize that potency), I would argue that this begs the question of the ontological baseline. Position alone is an incomplete description of a state; we must know its velocity. If the object is at A and already possesses a constant velocity toward B, its arrival at B requires no new efficient cause (no additional force). The actualization of its journey to B already occurred when the object was initially accelerated. The transition from A to B is simply the relational unfolding of that prior actualization.
This is how I reconcile it, and I don't see how this would create a larger metaphysical issue. Please let me know if it does!
If position is the ontological baseline, I'd need some proof that we can actively actualize the location of the stationary object from A to B without acceleration. If you could demonstrate a causal mechanism for this—say, a hypothetical equation like ψ = f(m, v/Δx) that operates independently of Δv—then I would concede. But as I see it, and as is clearly evident to the senses, an actualization from stationary A to B only ever occurs with a change in velocity. Without a change in velocity, an active change in local motion cannot occur.
Great article! Looking forward to reading a treatment on PSR next.
Are you guys attempting to critique Joe Schmid's existential inertia thesis? I would like to know and appreciate it if you guys do.
HOLY BASED MEGA AQUINAS GEM
I'm not sure that this fits with Galilean relativity, one of the foundations of Newtonian Mechanics. It seems, rather, that your position implies absolute motion or a preferred reference frame.
This is a genuinely interesting objection — one that occurred to me many years ago when I was first studying Aristotelianism.
The objection may be formulated more precisely as follows. According to Aristotle, the potency involved in local motion must belong to the mobile itself: motion is “the actuality of the movable insofar as it is movable,” and Aristotle explicitly says that “motion is in the movable” (Physics III.2–3, 202a7–14). Yet suppose that a body has a constant non-zero velocity relative to an inertial frame (S). Relative to a second inertial frame (S'), moving alongside the body at the same velocity wrt S, that body is at rest. It may therefore seem that the body is actually moving according to one frame but not according to another. If motion is the actualisation of a potency intrinsic to the mobile, must there not be some privileged frame relative to which the body is either really moving or really at rest?
The objection, however, confuses the intrinsic potency of the mobile with the relational determination under which its motion is measured. The potency to undergo locomotion — to occupy other possible positions and enter into new spatial relations — is genuinely founded in the mobile. Nevertheless, the complete actuality signified by a determinate velocity is not a merely intrinsic, monadic property. It includes an order to another physical term: the body has such-and-such a velocity relative to a given ICS.
This distinction is entirely Aristotelian. Aristotle defines relatives (a category of being) as things whose character is expressed by reference to something else: “Those things are called relative” which are explained through their reference to another (Categories 7, 6a36–b1). He also observes that “the same thing may be small in comparison with one thing, and great in comparison with another” (Categories 6). The same subject may therefore simultaneously possess apparently opposed relational predicates, provided that they are predicated according to different termini.
For example, Socrates may actually be to Plato’s left while simultaneously being to Aristotle’s right. There is no contradiction, because he is not both to the left and not to the left of the same person. Similarly, Aquinas remarks that “a column is on the right of an animal, without change in itself, but by change in the animal” (Summa theologiae I, q. 13, a. 7). A relational denomination may thus vary without a corresponding intrinsic alteration in the subject denominated.
The same answer applies here. The body is not both moving and at rest secundum idem et ad idem. Rather, it is actually moving relative to (S) and actually at rest relative to (S'). Both relations are objectively true. The observer does not create the potency or the motion merely by observing it; the reference frame supplies the second physical term according to which the body’s velocity is determined.
Consequently, the Aristotelian doctrine requires that the potency and the actuality of motion be grounded in the mobile, but it does not require every quantitative determination of that motion to be an intrinsic property possessed independently of all relations.
Thus no absolute preferred inertial frame follows merely from the principles of act and potency and the Aristotelian notion of local motion. Aristotle’s own cosmology did contain privileged places, such as the centre of the cosmos and the natural places of the elements, but that is a further physical and cosmological thesis — not something demanded simply by the metaphysics of potency and act.
You say: “the reference frame supplies the second physical term according to which the body’s velocity is determined.”
But that isn’t what Galileo is claiming. He is claiming that the reference frame is that according to which the body’s velocity is actual. Hence, the motion of a body relative to some reference frame is not a “quantitative determination” of that motion. It is that very thing that makes it to be motion.
A body can only be said to be in motion with respect to a reference frame. Wagner wants to say that a body is being actualized irrespective of a reference frame. He can do that, but he breaks with modern physics.
First, a small correction: Wagner is not the author of the article — I am. Wagner explicitly says this in the prologue he wrote. I am also a Mathematics graduate and studied both Galilean mechanics and Special Relativity, so don’t worry, the issue here is not unfamiliarity with elementary kinematics — and contrary to what you said, I would never, ever claim that local motion is “actualised irrespective of a reference frame”.
In Galilean mechanics, a body may have velocity (v) relative to an ICS (S) and velocity (0) relative to another ICS (S'). But obviously the frame does not efficiently cause either state. It is simply the second term relative to which the body’s velocity is specified — every body has a relation (which is a category of being) to an ICS. The body’s velocity v is actual wrt to S and the body’s rest is actual wrt to S’ — there is no contradiction and Aristotle never claimed anything contrary to this. In fact, if you push this to the last consequences, you will note that Galilean mechanics only could refute the notion of “impetus” as an actual mover inside the body, which I prove in the article to be an incorrect reading of Aristotle — as such a mover would exist in the case of referential S and not exist in the case of referential S’!
The correct Aristotelian statement is that potency to motion belongs to the mobile in relation to an ICS, and the determinate predicate “moving at (v)” is therefore also relational (and yes, also actual, because a predicate being relational does not mean it is not actual).
If a body is moving relative to S and resting relative to S', it is not moving and resting in the same respect because the category of relation resolves such a problem. If Aristotle didn’t claim relation as a category, your criticism would be valid — but that is not the case. If a body is in uniform rectilinear motion wrt S, potency is being actualised in the subject even if the referential is only relative and even if wrt to S’ the body is at rest (it doesn’t matter). The force of the criticism which I refute in the article is precisely in the fact that I can pick any object in inertia and, relative to this object, I can pick an ICS with respect to which the body is in rectilinear motion and hence is having potency actualised relative to such an ICS. What is the mover of such motion according to the Aristotelian kinesiological axiom? This is what the article answers.
The mobile has the intrinsic capacity to enter into different spatial relations. Which velocity is predicated of it depends upon the chosen inertial frame. Nothing of this contradicts anything in the article — it only contradicts the positions refuted in it.
If you have studied relativity, how do you maintain presentism (with respect to Philosophy of Time)? This is the position of Ss. Augustine, Boethius, Anselm, Thomas, etc (following Aristotle), but is seemingly in direct conflict with SR. One can adopt a neo-Lorentzian interpretation, but that just stands flatly in contradiction to how science is performed, and so is a lacking response. I ask this because an act-potency analysis best stands when contextualized with presentism (though I think it can stand within eternalism), and so would be in opposition to modern science. Ontological pluralism is another concern, as well.
It’s possible that I’ve misread these statements of yours:
1) “every body has a relation (which is a category of being) to an ICS.”
2) “The correct Aristotelian statement is that potency to motion belongs to the mobile in relation to an ICS….”
If so, I apologize.
In the context of 1), you seem to be using ‘relation’ and ‘category of being’ to refer to Aristotelian concepts. But Aristotle would never say that every (or any) body has a relation to a reference frame. A reference frame is a mathematical artifact, a being of reason. Bodies don’t have real relations to beings of reason, though some beings of reason, when being known by a mind, have real relations to bodies.
For 2), I’m not sure what you mean by a potency “belonging” to a being, much less belonging in relation to something. A thing is potential or actual. Potentiality and actuality are not qualities or habits of being, much less relations. A relation is itself an actuality of the thing, and not a comparison that the mind makes between two things (a being of reason). So potency can’t belong to a mobile in relation to anything.
For Aristotle, motion has three terms: what is being moved, what it is moving from and what it is moving to. For local motion, the termini of the motion are places, like Ithaca and Athens. So a local motion is defined by a place in which the moved thing is actually and a place in which the moved thing is potentially. When the moved things’s place is fully actualized at the terminus ad quem, it then rests and the motion is complete. The telos of a motion is rest - the completion of motion - at a particular place. Nowhere in that account can you find an ICS. Nowhere in that account can you fit an ICS.
Aristotle’s understanding of motion clearly relies on ”some privileged frame relative to which the body is either really moving or really at rest:” the terminus a quo and the terminus ad quem, the two places which the moving body actually and potentially is, and thus the terms that define that very motion.
Second of all, going back to your first response. You seem to be confusing velocity and motion. Velocity and motion are not the same thing. Velocitas is a quality of a substance in motion; it is an effect in the moved by the mover (unde velocitas motus est effectus receptus a movente in aliquo habente magnitudinem, Commentary on Physics Theta, L. 21). Thus, it is something intrinsic to the body. And so that velocity is not founded on a relation to some other being, whether of reason or otherwise. (Now, that velocity can be in proportion to another velocity, but said proportion would itself be a being of reason, a quality in the mind of the knower.) Again, no room in the definition for a reference frame defined by a velocity.
None of this means that your defense of the first way fails, it just means that it denies a really important foundation of modern kinematics. Which is fine, but you have to account for that.
I read this article not only due to personal interests but because I am doing a school project on the first way and wanted to respond to objections. I am newer to thomistic philosophy and so it is entirely possible I am just missing something, but how do per se causal series even exist in such a cases. The thing which sets say a ball into local motion in space does not need to persist in existence for the ball to keep on it's path. But say the ball encounters another ball, which is still, and the first ball actualizes in the second ball the potential to move in a certain direction at a certain velocity, how would this be a per se casual series, because the ball which moves relies on nothing but its current state to actualize the potential and nothing else. I know this may sound like a very stupid objection and it probably is but I am new and am finding it difficult to reconcile this. Unless I am wrong in my thinking tha the first way relies on per se causal series thst must be simultaneous in every actualization. Again sorry if this is all over the place.
I did not mean to write this in response to a comment but on the article itself and substack won't let me delete the comment.