Having just read “Stairway to the Mind” (by Alwyn Scott) I feel compelled to write some comments. I admit to having enjoyed the book for its coverage of various ideas, but I agree with Lee Corbin that he attacks a form of reductionism that I have never encountered. Even the atomic physicist agrees that one cannot practically calculate the spectrum of Lithium (3 electrons) from QM. At several points he emphasizes that the whole universe could not be harnessed to build a computer fast enough to leap some of the steps (on the stairway) that he enumerates. I agree. I even agree that it is an important observation. But I have not met a reductionist who ever claimed that you could. He seems to be battling a caricature of a reductionist. (Recent note)
I will come out with it and say that my ontology is relative. When I do math I will claim that there exist composite Mersenne numbers. When I argue about biology I do not claim that. It will strike some as Bizarre to deny the existence of a number just because I am considering another field. It may indeed not be necessary in that case but I suspect that is in others.
Sometimes it is not clear which of two theories is more fundamental.
Another particular experience with abstraction is in the construction of computers with some well defined instruction set. The correctness of a program written for that instruction set is in no way dependent on the manner that the instruction set was implemented in wires. Creatures implemented in software have no hope of determining the nature of the circuits of the machine, or even their existence.