Though it would still be quite reasonable to be a vitalist then, one hint you could have used if you were born at the right time: Lavoisier’s discovery that respiration and combustion have the same overall chemical inputs and outputs (“respiration is combustion”) + the idea of a thermodynamic engine, might lead you to conclude that despite the absurdity there must be invisible heat engines powering it all. Of course, Kelvin rejected the engine idea, and there’s no way I’d have done better; but probably some sorts of humanish minds could’ve figured out using only knowledge/upbringing of the time (and an ASI definitely could).
Though it would still be quite reasonable to be a vitalist then, one hint you could have used if you were born at the right time: Lavoisier’s discovery that respiration and combustion have the same overall chemical inputs and outputs (“respiration is combustion”) + the idea of a thermodynamic engine, might lead you to conclude that despite the absurdity there must be invisible heat engines powering it all. Of course, Kelvin rejected the engine idea, and there’s no way I’d have done better; but probably some sorts of humanish minds could’ve figured out using only knowledge/upbringing of the time (and an ASI definitely could).