Dear Sherman Jenkins,
I agree with you that FQXi is about thinking outside the box, not 'waiting for someone else to do it'. The problem, as you indicate, is that there are more 'new' ideas than 'correct' ideas, so it would be unwise to follow every new idea. This yields an inertia of old ideas or resistance to new ideas that is frustrating, but absolutely necessary.
I agree that the substance or 'stuff' is not time. That's why I said "the first five pages", in which Marcel presents the logic of substantial unity without yet giving his concept of it. And I agree that two types of 'stuff' does not work. My own preferred 'stuff' is the gravitational field, interpreted as a field, not as geometry. It is impossible to justify this in a comment, but I've touched on it in previous essays, and have done extensive work on it. The field has energy, hence mass, and it interacts with mass, hence itself, in non-linear fashion. With very few exceptions, physicists don't 'do' non-linearity. In my opinion non-linearity at high energy densities (such as are present at the big bang and in LHC-type collisions) has neither been analyzed nor appreciated. I believe it is a serious mistake to think the gravitational field is only relevant in weak field situations, such as between planets, or astronomically large situations, such as galaxies or black holes, and I have derived some fascinating results based on high density, rather than large size. I really hate to present such a radical idea in a short comment, but you asked my concept of the nature of the basic stuff, and that's it. I much prefer to lay out the details as I have done in Bell's case, and that is not possible at this stage of my results.
Thanks for reading my essay and commenting.
Edwin Eugene Klingman