John and Carl have started an interesting discussion on the nature of movement, is it only an illusion, or are objects really in motion as they appear to be.  Here are some thoughts on movement and motion as a contribution to that discussion:

If I follow the strict PoF line (my understanding of it of course) I would say that motion or movement (there is of course a qualitative difference in meaning between those two words which I will - conveniently - ignore for the moment) is recognised through my applying the concept "movement" to a percept or series of percepts.

For example, there is someone walking along the street.  I close my eyes for a few seconds, open them again and the person is still walking along the street.  I form the idea that the person was still in uniform motion while my eyes were closed - a reasonable assumption of course - and picture that to myself.

Now someone tells me "well actually, while your eyes were closed the person stopped, then ran a little bit and then started walking again just before you opened your eyes."  So I modify my mental picture of what took place.

Why do I mention this?  Because I think the question that can arise about motion is something like "what is motion really?  Is it really only a perception through the eyes or through thinking?" 

For the PoF point of view there are only the two polarities, percept and concept, to begin with.  The error I can see causing a little trouble here (from the point of view of PoF, I  have to stress again) is to assume that motion possesses a "thing in itself" or "ding an sich" ghostly existence which we can only speculate on.

So, what is the question being raised here really and how can we get at it?  I see someone in motion, say in a Eurhythmy performance.  Then, through reflecting on how the illusion of movement is created in the cinema, television and so on, the question arises, "what if the motion I perceive in the external world is actually similar to what happens on a TV screen?  What if the underlying reality is just like a series of frozen moments or snapshots that my brain assembles into an appearance of motion."

This kind of thinking is analysed in great detail in PoF, for example during the dissection of critical idealism in Chapter 4.  To come at it here, we can perhaps ask ourselves, "well what do I mean by an underlying reality?  What am I picturing to myself when I think of it?" 

So perhaps then I realise I am picturing to myself that objects in the world that appear to be in motion don't "really" change continuously in the way they appear to.  They are "really" just manifesting in a series of frozen states and it is "only" my thinking organism that "perceives" motion where none "actually" exists.

But I can make a little progress here if I ask myself, how could this "underlying reality" which is "really" a series of snapshots present itself to me?  Only through the polarity of concept and percept, permeated with my thinking activity.

With a TV screen I could carry out experiments of one kind or another - for example, I could perhaps adjust the refresh rate in some way until I recognise a series of still images following one another rather than continuous motion. 

What would be the equivalent for the perception of movement in space?  Are we imagining motion perceived in the physically perceptible universe as a kind of projection of an "underlying reality" that is static? 

Are we just mentally picturing that "underlying reality" as a kind of copy of our experience in the physical world and thus creating multiplying difficulties of understanding for ourselves through inventing a speculative "ding an sich" that is only present in our imagination?

For me personally I can perhaps then come to see that there is little point speculating at this level as there's no way to escape from the web of my own thinking. I understand the concepts "motion" and "movement" and can apply them correctly in situations like the ones mentioned above where I was watching someone walking, and later when I changed the refresh rate on a TV.

But unless I can point to a percept where the thought that "what I perceived as motion is really only a series of frozen snapshots" makes sense to me in other contexts, I am just tying my thinking up in fairly useless speculation that never comes to an end because it is always putting its supposed end point out of reach.

In the case of the person walking mentioned above, I can quite happily correct my thinking according to the reality.  In the case of a general speculation about the "real" nature of motion in the physical world things are not so concrete and it is easy to get lost in abstractions.

Not to say that there isn't an important truth to be gotten at here, please accept this rather long journal (if you persevere this far) in the spirit of just trying to clear some of the idealist "stuff" out of the way where it's not necessarily helpful...

A second train of thought would also follow from the example of the TV, somewhat as follows: If I know how TVs work, I know that the idea of displaying a rapidly changing series of static images to create the illusion of movement is actually embodied in the TV, the TV is a realisation of that idea in a sense.

Now how might that apply in our speculation on the "true" nature of motion?  Perhaps I imagine the "spiritual world" has "created" the "physical world" to present an "illusion" of movement to us. 

But what lies behind this thinking?  Presumably that a conscious being or beings in the "spiritual world" "knows" that "movement is only an illusion". 

But that begs the question which I could imagine myself asking, "dear spiritual being, what is motion really then?  Please explain it to me and show me what it really is.  As I have always found the concept "movement" very useful in my everyday life up until now.  Presumably you are not saying that the concept "movement" does not exist because I know it does from my everyday thinking experience, I would lose all respect for the spiritual world if you were to try and tell me that, I wonder if perhaps what you are really saying is that the concept "movement" has no meaning from your point of view?"