Aquinas' first and second proofs and their relation

[lmelahn]

Your explanation is called the hidden variables theory which has been discounted by things such as Bell’s theorem or even quantum entanglement.

If I understood correctly, quantum mechanics hinges on a mathematical construct called the “wave function” that effectively produces a probability map that such-and-such an event will take place or not. But probability is an inherently “gnoseological” notion (it is in the order of knowledge, not the order of being): it reflects my ignorance that something is taking place. It puts limits on that ignorance, certainly, but the ignorance remains.

(My only training in quantum mechanics is in the area of physical chemistry, so I admit I am not an expert. However, that is what we learned about electron orbitals and similar phenomena. The lobe-shaped p orbitals occur because the probability that the electron is located in the orbital’s node approaches zero.)

In any case, I have not seen any actual experiments that refute the principle of causality (as correctly understood: that every action depends on an agent whether that be a quantum with a dual wave-particle nature or not).

I do not see why that has to entail hidden variables. It may be that an electron, say, simply does not have a “location” or “momentum” in the classical sense of those terms.

 

[Tomdstone]

If I understood correctly, quantum mechanics hinges on a mathematical construct called the “wave function” that effectively produces a probability map that such-and-such an event will take place or not. But probability is an inherently “gnoseological” notion (it is in the order of knowledge, not the order of being): it reflects my ignorance that something is taking place. It puts limits on that ignorance, certainly, but the ignorance remains.

(My only training in quantum mechanics is in the area of physical chemistry, so I admit I am not an expert. However, that is what we learned about electron orbitals and similar phenomena. The lobe-shaped p orbitals occur because the probability that the electron is located in the orbital’s node approaches zero.)

In any case, I have not seen any actual experiments that refute the principle of causality (as correctly understood: that every action depends on an agent whether that be a quantum with a dual wave-particle nature or not).

I do not see why that has to entail hidden variables. It may be that an electron, say, simply does not have a “location” or “momentum” in the classical sense of those terms.

When you say that the model reflects your ignorance, it means that you are ignoring other hidden variables. But I think you are right on the causality question, even though the model is not a deterministic one.

 

[Richca]

The relation between the two proofs is much debated. In my opinion, St. Thomas in his First Way is beginning with what he considers the easiest proof, because it starts from what Aquinas calls “accidental change” (changes that do not cause the generation or corruption of substances; for example, human growth, melting ice, and the motion of projectiles are all “accidental” changes). That, according to Aquinas, is the easiest kind of change to observe.

The second proof simply opens up to consideration all kinds of changes and causes. In particular, he includes the generation and corruption of substances (for example, the conception and death of animals or chemical changes such as burning). This kind of change, which he calls “substantial change,” is less obvious than “accidental” change. (In the case of death, for example, we all see that the animal has stopped breathing, but it is less obvious that its very substance has changed to that of a dead body.)

As a sort of endpoint of his analysis, he even comes to the most profound of causes: creation. (Creation is different from all other causes, because it does not come about through a change. A change is always a passage from some previous state to the current one; when God creates something, however, He simply gives it is being, without using any pre-existing materials.)

(If you are brave, here is a good article on the subject of the structure of the Five Ways.)

Imelahn,
You make a good point here that the second proof which concerns cause and effect is more extensive than motion in the first proof especially if we consider the definition Aristotle gives to motion which is “the act of a being in potency in so far as it is still in potency.” Understood thus, if I’m not mistaken, this involves a qualitative, quantitative, or change of place and thus accidental changes. Motion taken in this sense is motion properly speaking and it does not entail a substantial change which I believe is what Aquinas says. Generation and corruption or perishing would not involve this kind of motion. However, since St Thomas uses the concepts of act and potency in the first proof and since act and potency so divide being that whatsoever exists either is a Pure Act, or is necessarily composed of Potency and Act, as to its primordial and intrinsic principles, maybe it is possible to extend the first proof to any kind of change though this may not be primarily what Aquinas has in mind.

I think what I was trying to convey in my first post is that since God is the first mover and first efficient cause, creatures are as a patient who receive the action of the agent, God. God is the first principle of the movements of creatures, the first mover. As the first efficient cause, God is not only the first principle of their movements, but of their whole being and whatever pertains to their being which is the effect of God’s action. St Thomas says “The preservation of things by God is a continuation of that action whereby He gives existence” (ST, I, q.104, art.1, reply to obj. 4). That action by which God brought things into existence when they first began to be, is the same action in preserving things in existence. Our existence in the here and now is the effect of God’s action in us. There is a sense in which it can be said that God is continually creating us. I believe St Augustine says this and Aquinas quotes him in one of his works. Sometimes I think we can sometimes think that God is way out there somewhere like at the edge of the universe or something. However, if we meditate on the truth that our very existence in the here and now is the effect of God’s action then God is more intimate to us than we are to ourselves as I believe St Augustine also says somewhere. Indeed, St Paul says, "indeed he is not far from any one of us. For ‘In him we live and move and have our being,’ (Acts 17: 27-28).

 

[lmelahn]

When you say that the model reflects your ignorance, it means that you are ignoring other hidden variables. But I think you are right on the causality question, even though the model is not a deterministic one.

Right, that is an important point. Causes, properly understood, need not be deterministic. The effect simply needs to depend on the cause.

(It is like billiards: the balls scatter when I hit them with the cue ball. The scattering depends on the impact of the cue ball, but there is no way to predict where each ball will go. Truly die-hard adherents to classical physics will say that if we just knew all the possible angles of incidence and momenta then we could in theory predict the motions, but for all practical intents and purposes, the motion is chaotic, if not exactly random.)

At least as regards Schrödinger’s Cat (things that are macroscopic like that), I don’t think a sound theory of knowledge permits any other interpretation than ignorance of the cat’s life or death. That is because our way of knowing something macroscopic like the cat uses macroscopic means: colors, light, touch, etc. We are not Geiger counters, but we rely on Geiger counters to detect quanta of radiation.

(I think those who think that the cat is half dead and half alive forget that both the cat and Geiger counter itself are “observers” of the phenomena: they depend on the action of the uranium sample, but once the effect is in place, it is already on the macroscopic level. If I understood correctly, that is precisely what is meant by the “collapse” of the wave function.)

It is much less problematic to say that the uranium atom is, so to speak, half-decayed, half-not-decayed until the Geiger counter reads it. The nature of the subatomic particles is such that their effects are not deterministic.

(Chemists see a very similar thing is so-called resonance hybrids. Take the molecule benzene, for example, which is a flat six-carbon ring. According to the classical VSEPR theory, the carbon-carbon bonds should alternate between single and double around the ring. In actual practice, we find perfect uniformity of electron density among all six bonds: a sort of one-and-a-half bond all around. Why is that? Because it seems that electrons are not little specks of negatively charged dust, as the first proponents of the atomic theory thought, but rather they occupy a “fuzzy” region in space. So a single electron is, so to speak, half in one bond and half in the other.)

 

[lmelahn]

Imelahn,That action by which God brought things into existence when they first began to be, is the same action in preserving things in existence. Our existence in the here and now is the effect of God’s action in us. There is a sense in which it can be said that God is continually creating us. I believe St Augustine says this and Aquinas quotes him in one of his works. Sometimes I think we can sometimes think that God is way out there somewhere like at the edge of the universe or something. However, if we meditate on the truth that our very existence in the here and now is the effect of God’s action then God is more intimate to us than we are to ourselves as I believe St Augustine also says somewhere. Indeed, St Paul says, "indeed he is not far from any one of us. For ‘In him we live and move and have our being,’ (Acts 17: 27-28).

I agree with you. Aquinas in his Quaestiones disputates de potentia, while showing that God is the Creator even of prime matter, uses an interesting expression: he says that matter is “concreated” together with the form.

A similar thing applies to the very act of creation. As you are probably aware, Aquinas considered that there are three fundamental compositions in creatures: substance/accident (in all creatures); matter/form (in material creatures); and essence/being (in all creatures).

Creation, therefore, entails the donation (datio) of being (esse) to a creature. This being (esse) is received into a potential principle called “essence.” But the essence does not pre-exist the being, any more than the matter pre-exists the form in a material creature.

So, although you will not find this expression in Thomas’ works in so many words, I think it is reasonable to say that a creature’s essence is “concreated” together with its being. The act of creation and the creatio continua are, in reality, a single act of creation: the donation of being to the creature.

 

[Tomdstone]

Right, that is an important point. Causes, properly understood, need not be deterministic. The effect simply needs to depend on the cause.

(It is like billiards: the balls scatter when I hit them with the cue ball. The scattering depends on the impact of the cue ball, but there is no way to predict where each ball will go. Truly die-hard adherents to classical physics will say that if we just knew all the possible angles of incidence and momenta then we could in theory predict the motions, but for all practical intents and purposes, the motion is chaotic, if not exactly random.)

At least as regards Schrödinger’s Cat (things that are macroscopic like that), I don’t think a sound theory of knowledge permits any other interpretation than ignorance of the cat’s life or death. That is because our way of knowing something macroscopic like the cat uses macroscopic means: colors, light, touch, etc. We are not Geiger counters, but we rely on Geiger counters to detect quanta of radiation.

(I think those who think that the cat is half dead and half alive forget that both the cat and Geiger counter itself are “observers” of the phenomena: they depend on the action of the uranium sample, but once the effect is in place, it is already on the macroscopic level. If I understood correctly, that is precisely what is meant by the “collapse” of the wave function.)

It is much less problematic to say that the uranium atom is, so to speak, half-decayed, half-not-decayed until the Geiger counter reads it. The nature of the subatomic particles is such that their effects are not deterministic.

(Chemists see a very similar thing is so-called resonance hybrids. Take the molecule benzene, for example, which is a flat six-carbon ring. According to the classical VSEPR theory, the carbon-carbon bonds should alternate between single and double around the ring. In actual practice, we find perfect uniformity of electron density among all six bonds: a sort of one-and-a-half bond all around. Why is that? Because it seems that electrons are not little specks of negatively charged dust, as the first proponents of the atomic theory thought, but rather they occupy a “fuzzy” region in space. So a single electron is, so to speak, half in one bond and half in the other.)

A lot of people believe that quantum mechanics works for a large number of particles and it is necessary to talk about ensembles, not just one particle when using the theory.

 

[thinkandmull]

The point is that Aquinas thinks motions could have always been, so motions shouldn’t even be in the argument for God at all. He could have argued merely from the argument that there can’t be infinite efficient causes, but that argument is undercut since he believes there can be infinite motions

 

[Richca]

The point is that Aquinas thinks motions could have always been, so motions shouldn’t even be in the argument for God at all. He could have argued merely from the argument that there can’t be infinite efficient causes, but that argument is undercut since he believes there can be infinite motions

Although St Thomas thinks motion could have always been, he did not believe that it had always been. St Thomas was a catholic and as a catholic he believed the universe had a beginning as a divinely inspired truth revealed to mankind by God through the Holy Scriptures and the teaching of the Catholic Church. Accordingly, anyone who holds that the universe had no beginning is in error in the mind of a catholic.

St Thomas does not believe it is possible to demonstrate from reason whether the world had no beginning or had a beginning. He believes that it is solely a matter of faith in God’s word that the world had a beginning. He also believes that it is far from impossible to hold that the world had a beginning not only from God’s word but also because God is a voluntary agent who acts by his will and who’s action does not involve movement or change in Him.

God is the absolutely first Being and he is an eternal and infinite being. God is also the creator of the world, the universe has received its existence from God. God is the first mover and first efficient cause of the world as St Thomas demonstrates in the first two proofs. Now, it is not impossible that the universe with its motion and time could have received its existence from God without a beginning in point of its duration. It is not impossible for a first Being, a first mover, and a first efficient cause who is eternal to produce an eternal effect.

However, supposing that God created the world, its movement and time without a beginning it does not follow that the universe would be eternal or infinite properly speaking. That which is eternal and infinite properly speaking is immutable and has its existence all at once which is God. A universe in motion and in constant change is measured by time and has its existence successively; it is only potentially eternal and infinite. If we suppose that there were an unlimited number of days in the past, today, tomorrow, and the day after will add to those previous unlimited number of days. This is an existence that is potentially eternal but not actually eternal, nor would the days of the world be an actually existent infinite but only potentially so as one follows another. There is no such thing as an infinite motion as the very word motion implies change, before and after, time, and succession. Not only this, the existence of the world is dependent on God, its first cause and first mover. Such being the case, even supposing the world received its existence from God from eternity, He could annihilate it at any moment. What then of the eternity and infinity of the world? Well, it wouldn’t exist!

Science appears to confirm the view that the universe had a beginning at least in regard to motion and time from the big bang and the singularity. How the singularity got there they have no clue. The cause of the singularity is the domain of the metaphysician. We can’t expect the natural sciences to provide us with the ultimate cause of reality because their particular fields of study are so to speak, inside the box.

The demonstrations in the first two proofs does not hinge on whether the universe had a beginning or not. The duration of the world is irrelevant to the proofs.

 

[Tomdstone]

The cause of the singularity is the domain of the metaphysician.

I don’t see why science is not allowed to say anything about the cause of the big bang singularity.