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The Unmoved Mover Argument – Part 12: What is Potentiality?

The Unmoved Mover Argument – Part 12: What is Potentiality? June 29, 2021

WHERE WE ARE

In his book Philosophy of Religion  (hereafter: POR), Norman Geisler provides an argument in support of the second premise of his Thomist Cosmological Argument (see pages 194-197).  Here is my understanding of the argument that Geisler gives in support of that premise:

52. But no potentiality can actualize itself.

THEREFORE:

53a. There is some actuality outside of every composed thing to account for the fact that it actually exists.

 51a. Every limited changing thing is composed of both an actuality (its existence) and a potentiality (its essence).

THEREFORE:

L1. There is some actuality outside of every limited changing thing to account for the fact that it actually exists.

THEREFORE:

2b. The present existence of every limited, changing thing is caused by another thing.

Before we can evaluate this part of Geisler’s argument, we must first have a clear understanding of what these claims mean.

 

CLARIFICATIONS NEEDED TO UNDERSTAND GEISLER’S ARGUMENT FOR THE 2ND PREMISE

This part of the argument is clearly steeped in concepts from Thomistic metaphysics.  If Thomistic metaphysics is fundamentally mistaken or confused, then this part of the argument is likely to fail under close examination.  If Thomistic metaphysics is fundamentally correct and logical, then this part of the argument is likely to be successful.

In any case, this part of the argument is UNCLEAR apart from careful and clear definitions and explanations of some basic concepts of Thomistic metaphysics.  The main question at issue for now is this:

Q1. Does Geisler provide us with clear definitions and explanations of the basic concepts that he makes use of in this part of his argument?

Premise (52), for example, MAKES NO SENSE, at least as it stands, apart from an explanation of Thomist metaphysics.  So, our main question at issue can be focused further:

Q2. Does Geisler provide us with clear definitions and explanations of the basic concepts in premise (52), so that we can have a clear understanding of what this premise is asserting?

Premise (52) consists of two main concepts, and so Geisler needs to provide clear answers to at least two questions of clarification:

Q3. What is a “potentiality”?

Q4. What does “X actualized Y” mean?

Furthermore, it is NOT obvious that (52) is TRUE, so Geisler also needs to provide some justification for this claim:

Q5. Why is it not possible for a “potentiality” to “actualize itself”?

 

WHAT IS A “POTENTIALITY”? (QUESTION 3)

Here is a passage where Geisler attempts to clarify the concept of a “potentiality” and attempts to answer Question 3:

Geisler states that a “potential” is “the mere capacity to have a certain kind of existence.”  That is a crappy definition. What the hell is “a certain kind of existence”?  How many kinds of existence are there?  Something either exists or it does not exist.  Do some things have SUPER existence? Do some things only have QUASI existence?  Do some things have MEGA-DOUBLE-SECRET existence? Talk about kinds of existence sounds like WOO-WOO pseudo-science bullshit.

However, Geisler does then go on to provide some specific examples, and that might help to clarify what the hell he means by the manifestly UNCLEAR phrase “a certain kind of existence”.   Geisler talks about “the potential for steel to be a skyscraper” and “the real potential” of an “empty bucket” to “be filled”.  So, steel has the potential to either be girders stacked into pile on the ground, or to be assembled together as the framework of a skyscraper.  A bucket has the potential to either be empty or to be filled with water.

We would NOT normally speak of these potential states as being “kinds of existence”, so the Thomistic terminology here is foreign to how we ordinarily talk about such things and states of things.  Steel has the potential to be used as the framework of a building, and buckets have the potential to contain water (and other liquids).  Air, at ordinary temperatures and pressures, does NOT have the potential to be used as the framework of a building, and (as Geisler points out) the flat surface of a desk top does NOT have the potential to contain water (or other liquids), at least not in any sizeable quantity (You could spray a mist of water onto the surface of a desk top, and the water would remain in place for an hour or more until it evaporated. But this would be a very inefficient way to transport water from one location to another!).

By some measures, what came to be known as a “skyscraper” first appeared in Chicago with the 1885 completion of the world’s first largely steel-frame structure, the Home Insurance Building. It was demolished in 1931.

But a particular steel girder either exists or it does not exist.  It’s “kind” of existence doesn’t change when it is moved from a pile of girders and assembled into the framework of a new building.  It existed in the pile, and it continues to exist in the framework of the new building; it does NOT take on some new “kind” of existence in this process.  The bucket exists when it is empty, and it continues to exist when it is filled with water; it does NOT take on some new “kind” of existence when filled with water.  So, when Geisler defines “A potential” in terms of the capacity “to have a certain kind of existence”, he is just muddying the water and failing miserably to clarify the meaning of this term.

It appears that there are not degrees of existence, and this casts doubt on the whole idea of “kinds of existence”.  However, the “potential” to be used in the construction of the framework of a skyscraper does appear to be a matter of degree.  Air clearly does not have the “potential” to be used as the primary material for constructing the framework of a skyscraper, nor does liquid water have such a “potential”.  But if water is frozen into large columns and bars, it could be used to construct a temporary framework for a one-story building.

Ice would, however, melt in warm temperatures, so it would be a poor choice to use it in the structure of even a small building (except for igloos in areas that stay freezing cold year round).  Ice also is not as strong as wood 2x4s.  You can use wood to construct the framework of a two or three-story building, and it would be sturdy and stable, in both cold and warm weather.  But wood  2x4s are not as strong as steel girders, so wood 2x4s would not work for construction of the framework of a skyscraper.  We can see that there are different degrees of suitability of materials for construction of the framework of a skyscraper:

Air & Liquid Water:  useless for constructing a framework for any building.

Frozen Water:  can be used to construct a framework, but not strong enough to support multiple stories, and melts in warm weather (over 32°F).

Wood 2x4s: can be used to construct a framework that is strong enough to support a few stories, doesn’t melt in warm weather, burns up at high temperatures (over 570°F), but is not strong enough to support dozens of stories.

Steel Girders:  strong enough to be used to construct frameworks for buildings with dozens of stories, will not melt in warm weather (steel melts at 2,500°F), and does not burn up at temperatures where wood burns up (steel burns at 1,500°F in pure oxygen, and at 2,246°F in air).

The suitability of a material for use in constructing the framework of a building is a matter of degrees, because (a) there are different degrees of strength, and there are different degrees of susceptibility to melting, and  different degrees of susceptibility to burning.  Thus, there are different degrees of “potential” of different materials for use in construction of the framework of a building, and of a skyscraper.

The “potential” of something to be used for a particular purpose is typically a matter of degrees and typically is a matter of more than one criterion.  Some things or materials might be completely unsuitable, while some things/materials are somewhat suitable, and some things/materials are very suitable or ideal for the purpose at hand.  The “potential” of something to be used for a particular purpose depends on the properties or characteristics of that thing that are relevant to the particular purpose under consideration.

Steel girders have “great potential” for use in construction of the frameworks of skyscrapers because they are very strong (stronger than wood 2x4s), because they don’t melt in ordinary temperatures, and don’t burn, except at extremely high temperatures.  These various properties or characteristics of steel girders are what make steel girders very suitable for this particular purpose; they are what give steel girders this “great potential” related to the purpose of use in construction of the frameworks of skyscrapers.

Here is an summary (in more abstract terms) of how we understand the idea of the “potential” of a steel girder to be used in the construction of the framework of a skyscraper:

The “potential” of thing T to perform function F depends on various properties of T that are relevant to how well it can perform function F

How do we determine whether thing T has the “potential” to perform function F well?

  • One obvious way of making this determination is to observe T performing function F, and evaluating how well it is performing that function.
  • Another way of making this determination is by making inductive inferences about T based on how well other things that are SIMILAR to T perform function F.   We might observe many wood 2x4s in the frameworks of many different buildings, and based on many such observations, we may reasonably infer that some particular 2×4 is well-suited for use in the construction of a framework for a two-story house or apartment building, and based on many such observations we may reasonably infer that some particular wood 2×4 is NOT suitable for use in the construction of the framework for a 40 story office building.
  • A third way of making this determination is on the basis of relevant properties, such as strength in the case of materials for use in constructing the framework of a building.  Strength tests could be made on a particular 2×4 to determine whether it was strong enough for the intended framework that is to be constructed.
  • A fourth way of making this determination is on the basis of relevant properties of things that are SIMILAR to the particular thing in question.  Strength tests can impact the thing being tested (the test itself can break or weaken the thing), so we might run tests on things that are very SIMILAR to the particular thing in question.  We might run tests on a random sample of 2x4s from a particular source of lumber, and if 100% of the samples pass the test, we might reasonably infer that other 2x4s from that source of lumber are also strong enough to pass the test, and thus suitable for use in construction of a framework for a specific building.

So, we can either (a) observe the particular thing performing the desired function, or (b) we can observe SIMILAR things performing the desired function, or (c) we can check or test the particular thing for the relevant properties that make it suitable for that function, or (d) we can check or test SIMILAR things for the relevant properties that would make them suitable for that function.  There may be other ways to determine the “potential” of a thing T to perform a function F well, but these are some of the important ways we have of making such determinations.

 

POTENTIAL VS. POSSIBLE VS. ACTUAL

There are three closely related concepts that I think we need to understand in order to have a clear understanding of what the term “potential” means in the context of Geisler’s Thomistic Cosmological Argument: potential, possible, and actual.  I think we need to understand how these concepts relate to each other.

In Aristotle’s theory of change, whenever any change occurs some potential has been actualized.  When a green banana turns into a yellow banana, we say that the green banana had the “potential” to become a yellow banana.  We KNOW that this particular green banana had this potential because we observed that it actually became a yellow banana.  In other words, when a property of a thing ACTUALLY changes, we infer that the thing had the POTENTIAL to have the new property.  The banana was ACTUALLY green, and had the POTENTIAL to become yellow, and then at some point it was ACTUALLY yellow, and no longer green.  The change in color of the banana was a POTENTIAL that became ACTUAL.

Because this banana is now ACTUALLY yellow, we know that is is POSSIBLE for this banana to be yellow, because what is ACTUAL is necessarily logically possible. But does having the POTENTIAL to be yellow the same thing as it being logically possible to be yellow?  I know that Ed Feser rejects equating these two concepts.  But I’m not sure whether Geisler distinguishes these two concepts.

One important difference, it seems to me, is that the POTENTIAL to be yellow ceases to exist when the thing in question is ACTUALLY yellow.  But the logical possibility of being yellow does NOT cease to exist when the thing in question is ACTUALLY yellow.  When the banana turns yellow, it no longer has the POTENTIAL to be yellow, and it is ACTUALLY yellow.  But we infer that it HAD the potential to be yellow previously, when it was still completely green.  In the case of logical possibility, when the banana turns yellow, it is still logically possible for that banana to be yellow, even while it is ACTUALLY yellow.  We infer not only that this was logically possible when the banana was completely green, but that it is still logically possible now that the banana is completely yellow.

Having the POTENTIAL to be yellow is a kind of physical possibility for the green banana.  We know from many experiences with green bananas that they often turn yellow over a period of days.  The chemical and biological nature of bananas makes it so that they tend to turn yellow as they age.  So, a banana turning from green to yellow is NOT merely a logical possibility, it is a tendency of (some varieties of) bananas to go from green to yellow over a matter of days after being picked.  This tendency is based on the chemical and biological nature or composition of bananas.   It is logically possible for a green lime to turn yellow a few days after being picked, but limes don’t tend to do this.  The mere logical possibility of some change in properties is NOT sufficient to bring about that change.  Limes don’t have the POTENTIAL to turn yellow in a matter of days after being picked, but they do have the logical possibility of turning yellow days after being picked.  Bananas have the POTENTIAL to turn yellow in a matter of days after being picked, because they have a nature or composition that gives them a tendency to do so.  This tendency to turn yellow in a matter of days is MORE THAN just a logical possibility for a banana, it is something more like a physical possibility for bananas to turn yellow.

Does an ACTUAL change in property logically imply that a thing had MORE THAN just a logical possibility of undergoing that change? Some changes are random and extremely rare.  According to quantum physics, it is possible for all of the air molecules in a room to quickly move to one small area in the corner of the room, causing any people or animals in the room to asphyxiate.  But this possibility is so extremely unlikely, so extraordinarily improbable, that we can safely assume this will never actually happen.  Since the laws of chemistry and physics are based upon such extreme improbabilities, it is logically possible for a law of chemistry or physics to be broken.  I take it that this means that an ACTUAL violation of a supposed law of physics is logically consistent with that law being a true law of physics.

 

TO BE CONTINUED…

In the next post on this topic, I will try t clarify the meaning of Geisler’s term “X actualized Y” (Question 4), and look into why he thinks it is not possible for a “potentiality” to “actualize itself” (Question 5).

P.S.  I hope that when I get around to examining Feser’s Thomist Cosmological Argument, that Feser will make more of an effort than Geisler to define and/or clarify the basic concepts in his argument.  The fact that Geisler makes so little effort to define or clarify his most basic terms leads me to suspect that he himself is UNCLEAR about the meaning of those basic terms, and that he literally does not know what he is talking about.

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