The second level is what I call substance, mostly the theory that guides my looking at examples, the concepts and their interconnections, also their connections with other sorts of theory (like film theory, or the psychology of dreaming). This is the condensed, sedimented basis of everything that happens on the surface layer. For instance, the rough division into areas of the instances of unreality is based on a structure which is itself part of the substance layer. Concepts such as that of spaces of possibilities which I recently looked at, or broader accounts such as that of the interplay of imagination and reflection belong here. These are what is applied at the surface level. They are, however, not just applied, but also extended and corrected by insights found on the surface. Discussion on the surface has a validating role for the elements in the substance layer.
On the third level, I explore connections, similarities and differences with philosophy. Mostly, this means studying philosophy for analysis that might come in helpful, for precursors or providers of frameworks which bring a basis for my own project, and possible objections to my views.
The philosophy layer is a reflective one; it reflects on theory, not on the forms of unreality themselves. Concepts from philosophical works or contemporary debates might also appear on the substance level. If they do, they throw light at surface phenomena (such as what happens in a novel). If they appear on the philosophy level, however, they help explain underlying theories or concepts (which are on the substance level and thus in turn help explain surface phenomena). And finally, the relation between substance and surface itself, and other relationships between layers, are reflected here.
There is (I think) another, fourth layer, which I call the ground. That's where the philosophy parts are based in. For instance, I have to decide sometimes which philosophical frameworks I would accept for my purposes. I think there must be something in which such a decision would be founded, though I find myself unable to articulate this any clearer right now. I thus won't say much about that level, though it may happen that I'll from time to time allude to it. (Probably primarily in the form of appeal to deep intuitions.)
These layers imply no ranking (working on the surface level is no less important that working on the philosophy level). They're rather intended as a quick help for orientation for me, while writing, and for you, while reading. If you like, you can consider them as a tool for roughly grouping or classifying my postings: usually you should be able to tell at which level we're currently discussing things. Also, don't interpret too much into the terms I've used for the layers. They're chosen in part for their suggestive and pictorial characteristic; there is no deeper truth (or even a metaphysics) to be found in them. (At least none that I intended to put there.)
 This is another term that has a long history; I don't want to allude to the more technical uses of this term in older philosophy; the use that I have primarily in mind is rather as in "His allegations have substance." As a name for one of the deeper layers, it connects also to the original Latin substare, from which it is derived.