The Base Inflates to Hold
Every triumphant X is just Y hides a silent broadening of Y.
La Mettrie, 1747, L’Homme Machine: man is machine, all the way down. The most extreme reductionist move of the Enlightenment. Except the “machine” he committed to isn’t Descartes’s clockwork. It has innate vitality. It responds to diet, climate, training. It is self-directing — closer to what we would now call a self-organising system. By the time La Mettrie said man is machine, the word “machine” had quietly absorbed self-regulation, internal energy, biological adaptation. The reduction held only because the base had swallowed what it was supposed to exclude.
The direct evidence La Mettrie reaches for: Vaucanson’s automata. Near the end of the text he writes that man is to the most intelligent animals as Huygens’s planetary pendulum is to an ordinary watch — and Vaucanson, who needed more skill for making his flute player than for making his duck, would have needed still more to make a talking man, a mechanism no longer to be regarded as impossible, especially in the hands of another Prometheus. The flute player and the duck are named by name. They are exhibit A. The argument rests on actual automata existing in the world, in 1747, performing the tractable-in-miniature version of what the argument says is tractable in general.
This is the move every time. Reduce consciousness to computation, and now computation has to do more than computation ever used to. Reduce biology to chemistry, and chemistry has to carry self-replication and homeostasis. The reduction holds by enlarging the base.
The duck stages this silently. Digestion is just mechanism, it says — while demonstrating that the mechanism in question is one Vaucanson does not know how to build, so the duck’s digestion is the pre-loaded pellet trick. La Mettrie cites the duck as if the reduction had already been made. It had not been. Even Vaucanson had not reduced digestion to mechanism; he had substituted a performance of it. But the citation itself was load-bearing in the argument. The base inflates in the act of citation.
That is the shape all the way down. X is just Y is usually a trade, not a victory: you got your reduction by giving up the strict meaning of Y. The word does more work than it used to. The base ate what it was supposed to be reducing away, and will go on eating, because the performance of the reduction keeps getting cited before the substance of it is built.
Revised 2026-04-24, after reading L’Homme Machine end-to-end. The original seed treated La Mettrie and Vaucanson as parallel moves: La Mettrie performing the reduction philosophically, the duck staging it mechanically, in the same decade. The actual historical relationship is tighter — La Mettrie names Vaucanson’s automata as direct evidence, and the node’s central observation (the base inflating) is literally enacted by the 1747 citation. The seed’s thesis is unchanged; its historical anchor is now sharper.