Does "Walking" exist, Dusman?

Here's a quick response a section in a recent post by "Dusman", in which we find Dusman, a reducing philosophical materialists to absurdities via the magic of presuppositional apologetics.

Dusman advances the following argument:

Argument One:

1. Material things are extended in space.
2. Logical laws are not extended in space.
3. Therefore, logical laws are non-material.
4. Materialism posits that non-material entities do not exist.
5. Therefore, logical laws do not exist.

Just thinking about that, I wonder if Dusman thinks the activity of "walking" is a materialist absurdity:

The "Walking" Corollary:

1. Material things (like legs) are extended in space.
2. "Walking" is not extended in space.
3. Therefore, "walking" is non-material.
4. Materialism posits that non-material entities do not exist.
5. Therefore, for the materialist, "walking" does not exist.

If you've spent any time wading into the rhetorical devices of presuppositional apologetics, you'll anticipate that Dusman might just want to assert that materialist really don't have any basis for believing in "walking" or any similarly derived concept.

Walking, as a concept, has physical infrastructure -- the brain-state(s) that reify the concept in the mind -- and is thus perfectly "real" and extant as a physical entity, but the subject of the concept is abstract.

Logic, like the activity of walking, isn't a physical entity beyond the electro-chemical patterns of the brain that holds the concept. And logic, like walking, is descriptive of natural properties and phenomena. Both are useful abstractions for understanding and describing the world around us, but they are abstract beyond their physical housing as brain-states. When I get out of my chair and walk across the room, I have not created a "walking" when I get out of my chair and walk across the room, nor destroyed a "walking" when I sit down again. The concept in both cases -- "walking" and logical principles -- is just that: conceptual, and thus real and extant in the form of brain-states. The referents of the concepts are real and existent in the straightforward sense; legs are "extended objects" in space/time, and "walking" is an abstraction about the patterns of movement and activity of the legs.

I don't know who the philosophical materialists are that Dusman can get to take him seriously with the argument he presents, let alone find themselves reduced to absurdities, but whoever they are, they aren't philosophically anything much at all, if they are, in fact, actual in the first place. In any case, all the materialist needs to do is show that "walking" doesn't exist under the terms of Dusman's argument, which winds up making Dusman dealing with the absurdities, not the materialist. Does Dusman believe the materialist thinks "walking" doesn't exist, or must disbelieve in walking as a materialist? It's as if the concept of abstraction itself has somehow eluded him, or that he supposes that the concept of abstraction somehow necessarily eludes the materialist.

In any case it's too bad Dusman doesn't make himself available to actual responses to his arguments, to see who is really trafficking in absurdities.

What say you, materialists? Does "walking" exist? Has Dusman removed that from our cognitive reach along with logic?