Excellent and thank-you! I'd somehow forgotten about Nerst and would have linked to his work directly. I think the additional value Hahn's ontology brings to erisology is an explicitly positive gradient, in a hill-climbing sense. For any disagreement, Hahn's ontology allows the parties to accept some level of agreement (Where are we on the agreement landscape?) and have an objective target for improvement, assuming good faith on everyone's part. I'm inclined to try to communicate it to Nert based upon your linking the two!
Why is there no Section IV? It's a delicious irony of reading a book review of Gödel, Escher, Bach on LessWrong that upon noticing that the Latin-numbered sections jump from 3 to 5 (III, V) I'm left wondering if that's simply a silly mistake or if the omission of section IV is some profound meta-self-referential in-joke on the part of the reviewer that I'm just not clever enough to see.
The Industrial Revolution seems largely the result of a particular positive feedback singularity, that the steam engine, which converts iron, coal and water into mechanical energy that can be used to pump water, was concocted in England, where high quality veins of coal and iron ore happened to be located deep underground beneath the prevailing water table. The steam engine pumping out mines, with steadily increasing power and efficiency, facilitated access to more iron ore and coal, which could be more efficiently transported by steam locomotives riding iron rails and by steamships, to foundries fired by coal to make more iron used to make steam engines, trains, rails and steamships. And off we went to the stars.
Once you get steam engines, you get mechanical engineering as everyone races to figure out how to do even more with less. Feedback control theory comes directly from the steam engine too (James Clerk Maxwell analyzing Watt's Flyball Governor). The alien planetary autocrat surely wants better steam tech to out-monument the last guy. So steam plus self-interest probably gets you space travel independent of democracy or free markets.
One can't prove a negative, of course, but on an iron-nickel planet in the habitable zone with carbon-based life using water as a solvent, steam engines do seem inevitable once you get large scale adoption of iron tools. There's an interesting paper or three to be written about Drake's f_c for the mechanics and thermodynamics of alternate steam engine triples (metal, fuel, fluid) potentially available on classes of exoplanet by formation and composition.