David and Julie,
Congratulations on a very engaging and thought-provoking essay. If I have so many comments (below), it is directly in proportion to how very stimulating I found your work:
1. [p1] One must ask, what does it mean for there to "exist" a complete explanation for something, let alone for everything? Where does it exist? Does an explanation mean a cause? If explaining is the act of an agent, then clearly there are many things for which no explanation "exists". Leibniz himself distinguished between necessity and certainty.
2. 'Mysterianism' [p1] seems a prejudicial category. The fact that there are "brute facts" at any given time is relative to state of knowledge at that time. What does it mean for something to be "in principle incomprehensible"? This represents a gesture by the rational mind to trump uncertainty by "proving" that it is necessary--rendering it rational on a meta-level. It is simpler to admit that there is no justification to assume that knowledge can be complete--including the knowledge that it must be incomplete.
3. I am not convinced that energy "merely represents the ability of a concrete thing to change" [p2] What about the ability to cause other things to change?
4. The idea that properties can average out to net zero is seminal. It makes all properties, microscopic or macroscopic, relative to scale and essentially statistical--that is, ultimately the result of brute facts (statistical data).
5. I would agree with Parmenides that the world must have "always" existed (in some form), and for similar reasons add that it can have no bottom or top (infinite in both directions of scale).
6. [p3] I would like to know more about Peter Inwagen's idea that "we can only understand what logically follows from what is logically necessary or self-evident". Can you direct me to a particular source? I relate this idea to Vico's verum factum, since logical systems are human constructions. Also, Wikipedia says about Inwagen's ideas in Material Beings, that "all material objects are either elementary particles or living organisms. Every composite material object is made up of elementary particles, and the only such composite objects are living organisms. A consequence of this view is that everyday objects such as tables, chairs, cars, buildings, and clouds do not exist." This intriguing idea suggests that only organisms are intrinsically "organized", because they self-organize. All other appearances of organization are human constructs--either projections upon nature (clouds) or actual human artifacts (chairs, cars, etc).
7. We "have to accept some brute facts" not in order to save free will but because (on the basis of experience so far) we are never in a position to do otherwise. If the world is indefinitely complex, then in principle there will always be brute facts; theory can never fully capture indefinite complexity.
8. There is no a prior reason to think that "explanatory chains must terminate" [p3, Sec 5]. I agree with the view you call "organicism", but would point out that PSR and the "reasonableness" of the Systems approach may be wishful thinking on the part of reason itself. Nothing compels PSR but our desire for certainty.
9. [p5, Sec 7] 'Systems' are human creations projected onto Nature. That is, all systems are inherently deductive systems; their fit to real natural structure is an empirical matter. If it is "reasonable to assume PSR", it is because PSR is an imperial decree of reason itself.
10. I submit that empirical facts cannot be "self-evident or logically necessary". Only theorems provable within a deductive system can be so. That is, self-evident truths are human assertions. "Brute facts" may be "placeholders for discoveries and explanations yet to come whether or not "we assume PSR". What limits discoveries at deeper levels may not be any ontological structure or an ultimate bottom but epistemic limits.
11. [p6] It does not follow from "the 'ultimate stuff' must have energetic properties" that it "must have energy on average". Quite the contrary, in your earlier discussion (Sec 4), the instantaneous properties of virtual particles average out to "nothing".
12. [p8, Sec 10] Personally, I don't believe in any resolution of the mind-body problem that relies on "primitive properties of fundamental matter", other than its ability to self-organize. I believe the solution lies elsewhere. Penrose's "microtubules", for example, are no more plausible than Descartes' pineal gland.
thanks again,
Dan Bruiger