Classical Theism, Philosophy, and Religion Forum / Aquinas' First way versus the evolution of a star

**Posted by Johannes** 12/20/2017 3:58 pm

The First Way can be stated as:

"Whatever is changing is being changed by something else."

However, any star is fusing hydrogen into helium and then into heavier elements, and over time evolving from one type of star into another, wholly on its own, irrespective of the presence of any other object in the universe.

Any thoughts?

**Posted by RomanJoe** 12/20/2017 10:11 pm

Johannes wrote:
The First Way can be stated as:

"Whatever is changing is being changed by something else."

However, any star is fusing hydrogen into helium and then into heavier elements, and over time evolving from one type of star into another, wholly on its own, irrespective of the presence of any other object in the universe.

Any thoughts?

I don't know much about the fusion and evolution of stars, but it seems like this could just be a case of constituent parts acting in causal relation with each other. That is, the star itself may not have something outside of it changing it, but its various constituents all operate via the principle of motion. The star is, in this respect, self-moving. But it's self-moving in the same manner that a dog walking across a lawn is self-moving. That's my two cents.

Last edited by RomanJoe (12/20/2017 10:11 pm)

**Posted by ficino** 12/21/2017 7:52 am

Johannes and RomanJoe, you both seem to be denying the thesis that every change in the universe is necessarily the terminus of a hierarchically ordered series of causes or movers, all instruments of an Unmoved Mover/Uncaused Cause. Do you mean that the star and the dog are self-movers that don't need to receive motive power throughout the motion from a UM? Or do you mean that the UM acts on the star and dog immediately, w/o intermediary instruments, to move them?

**Posted by Johannes** 12/21/2017 9:14 am

ficino wrote:
Johannes and RomanJoe, you both seem to be denying the thesis that every change in the universe is necessarily the terminus of a hierarchically ordered series of causes or movers, all instruments of an Unmoved Mover/Uncaused Cause. Do you mean that the star and the dog are self-movers that don't need to receive motive power throughout the motion from a UM? Or do you mean that the UM acts on the star and dog immediately, w/o intermediary instruments, to move them?

That thesis is philosophical, not physical.

I am just noting that a star is not, at the physical level, "being changed by something else".

Therefore, if the First Way is based on the observation that, at the physical level, "Whatever is changing is being changed by something else.", then it is based on a wrong notion.

**Posted by GeorgiusThomas** 12/25/2017 5:23 am

The basic reply to this, I think, is that stars are not relevant examples, as they are, like planets, mere accidental unities. They are hence more analogous to, say, human societies, which do have tendencies and regularities and are hence identifiable for the purposes of certain queries, but are not substances.

Choosing a different analogy, Fr. William A. Wallace writes in his The Modeling of Nature:

"The unity of a star would seem to be analogous to the unity of the earth: largely a mass of different substances held together by natural forces of one type or the other. And if the evolutionary model of stellar development is correct, a star can have a history even though it has not a single nature like an oak or a chipmunk (p 69)".

I realize this wouldn't be too useful to someone critical of the general A-T approach to the subject, but this does seem to address the immediate worry.

**Posted by GeorgiusThomas** 12/25/2017 7:19 am

Also, I do not think that there's any need on the part of the Thomist to think that the 'movement' has to be "at the physical level", where this means the set of realities treated in (modern) physics. After all, natural motions are caused ultimately by the form, the latter being a "metaphysical" part.

Last edited by GeorgiusThomas (12/25/2017 9:07 am)

**Posted by Johannes** 12/26/2017 4:09 pm

GeorgiusThomas wrote:
Also, I do not think that there's any need on the part of the Thomist to think that the 'movement' has to be "at the physical level", where this means the set of realities treated in (modern) physics. After all, natural motions are caused ultimately by the form, the latter being a "metaphysical" part.

Yes, everything in the first principle is at the metaphysical level. It is clear in the article on this subject in Feser's blog, starting in the paragraph beginning "Indeed, for the Aristotelian-Scholastic tradition," and especially in the following, beginning "All the same, natural substances are not the source of their activity in an absolute and ultimate sense.", whose content is restated briefly in the last section of the article, "A purely actual first mover?".

Last edited by Johannes (12/26/2017 4:10 pm)