ArmandoAlvarez wrote:

That is helpful.  I don't see that any of it is logically necessary because it seems like Paramenides' definition of "being" is question-begging.  Only by assuming everything is one unchanging substance do we come to the conclusion that change is impossible. But I'm probably still misunderstanding.
I said this in the other beginner's question forum, but I don't see how potentiality is logically necessary.  Before I studied philosophy, if you asked me what made change possible, I would say it was the flow of time, and if you asked me what time is, I would say, "I don't know."  I know lots of ink has been spilled by philosophers and physicists on the nature of time, but for the most part it seems like it's still a great mystery.
If you remove time, I would think you remove the possibility of change.  Thinking of X as potential Y doesn't seem helpful.  
I think part of my problem is that I'm hypostatizing potentiality in the wrong way-I think I'm drawing in my mental picture of physics class where they have the little bar graph of potential energy and kinectic energy and the two amounts sliding back and forth as a ball bounces.  I know that the tendency to bring mental images is a big danger in metaphysics.

Well, I would say this: is there a difference between time and things? Is everything "just time" or is there a difference in nature? For classic philosophers, time was a consequence of being not a necessary conditional of being. Change made for time; not time, change: no change, no time.

You are hardly alone in feeling that the actuality and potentiality distinction seems superfluous. We should remember, however, that these terms are primarily metaphysical in nature. Consequently, physics or empirical science are apt to ignore or assume them at leisure, even though they are, as it were, always riding under the surface.

Logical thinking is perhaps the easiest way to come to see the need for these specialized terms. Consider the following question:

Is wood potentially charcoal?

As I said in another post, logically considered this question - as formulated - actually raises a lot of difficulties, even though most would agree in ordinary conversation that wood can become charcoal. However, from the logician's point of view, this can sound almost absurd. Wood itself does not become charcoal and has no potentiality to become (itself) charcoal. To admit that would be to deny there is any difference between wood and charcoal in the first place, as they would have to be the same thing and, consequently, there would be no change at all. Of course, philosophy provides us with some terms that can help us here, especially the distinction between substance (which can change) and essence (which cannot change). Further distinctions between Form and Matter and finally Act and Potency also start to become relevant.

Last edited by Timocrates (7/11/2015 4:23 pm)

ArmandoAlvarez wrote:

Timocrates wrote:

Well, I would say this: is there a difference between time and things? Is everything "just time" or is there a difference in nature? For classic philosophers, time was a consequence of being not a necessary conditional of being. Change made for time; not time, change: no change, no time.

You are hardly alone in feeling that the actuality and potentiality distinction seems superfluous. We should remember, however, that these terms are primarily metaphysical in nature. Consequently, physics or empirical science are apt to ignore or assume them at leisure, even though they are, as it were, always riding under the surface.

Logical thinking is perhaps the easiest way to come to see the need for these specialized terms. Consider the following question:

Is wood potentially charcoal?

As I said in another post, logically considered this question - as formulated - actually raises a lot of difficulties, even though most would agree in ordinary conversation that wood can become charcoal. However, from the logician's point of view, this can sound almost absurd. Wood itself does not become charcoal and has no potentiality to become (itself) charcoal. To admit that would be to deny there is any difference between wood and charcoal in the first place, as they would have to be the same thing and, consequently, there would be no change at all. Of course, philosophy provides us with some terms that can help us here, especially the distinction between substance (which can change) and essence (which cannot change). Further distinctions between Form and Matter and finally Act and Potency also start to become relevant.

That is both helpful and confusing, but I'm grateful for your response.  I would have thought wood being potential charcoal would be one of the more basic examples of X being potential Y.  What would be an example of X being a potential Y?  Are two liters of hydrogen gas and one liter of oxygen sitting in cannisters next to each other potential water?  Is an acorn a potential oak tree?  Is a man with two hands a potential man with one hand?  If any of those Xs are potential Ys, how do any of those examples differ from wood being potential charcoal? Or am I just misusing the term "potential" entirely?

Well, that's the thing. It's properly the material principle of wood that has the potentiality to be (or become) charcoal. All I am drawing out is that the essence of things do not change and are not interchangeable.

We see this more clearly if someone were to say that "black is potentially white." There more people would see a problem. We would probably say instead that this black surface is potentially a white surface. In that latter description it's obvious that the potentiality is on the part of the surface (and whatever it happens to be made of) that is the material basis of the colour.

Last edited by Timocrates (7/11/2015 6:45 pm)

Thanks for the replies Scott and Timocrates.  That makes a lot of sense.  It also gives me the feeling that the waters are deep as soon as you step off the shore.
 

I've thought about everything you guys have said and I'd like to ask a question that perhaps is only a stumbling block to me. The way I was presented Aristotelian philosophy in high school and college was that Aristotelian philosophy is tied up with Aristotelian science and therefore can be safely ignored.  That Aristotelian metaphysics, including actuality and potentiality, was developed in part as a response to Democritus and atomism, but that atomism was right.
I know that you need metaphysics before you have any science at all.  But I clearly don't understand what we mean by act and potency, or why the existence of act and potency is a logical necessity.  
The bias I have from this background leads to a voice in my head asking "What's the use of thinking of the wood as potential charcoal, or thinking of grass a potentially a sheep?  Just talk about the science behind the process."  I'm glad that you've cleared up that the wood isn't potential charcoal, that although a sheep might eat grass, the grass isn't a potential sheep, etc.
Let's imagine we have a universe that consists of a single ball moving around in a vacuum.  Do we need the ideas of act and potency to describe change in this universe?  If so, do we say that the ball is actually at point A and potentially at point B?
I ask because so much of the visible change we see in our real universe is just the movement of particles (and energy).

Thanks for the reply, Timocrates.  I think I am both understanding more and more confused.
Why is me being awake now and asleep later a problem?  I'm not awake and not-awake at the same time.  I'm doing one and then I'm doing the other.  Every articulation of the law of non-contradiction I've heard goes along the lines of "Nothing can be both X and not-X at the same time."  I don't see why we should assume that something can't be both X and not-X at different times.
Is the question "How can anything be itself with varying attributes?"  Like how can I be me despite being composed of different cells today than yesterday, despite being taller than I was when I was a child, etc.?  If that's what these concepts are getting at, I can see how that's a useful question and how act and potency might be an answer to that.
And how about my question about motion. Do act and potency describe motion, or is that some other concept.  Do we say that a ball that is at point A is potentially at point B, or am I misusing the terms?