www.lesswrong.com/posts/d5NyJ2Lf6N22AD9PB/where-to-draw-the-boundary

This parenthetical collapses two historically distinct ideas into one.

Mesmer’s animal magnetism was his theory that healing worked through a universal magnetic-like fluid or force. By contrast, hypnosis/hypnotism was a later term and framework that emerged in the 19th century. A peer-reviewed historical review in Deutsches Ärzteblatt International states that Mesmer’s animal magnetism is "the precursor of modern hypnosis," which means it preceded and influenced hypnosis rather than being identical to it. The same review also explains that James Braid later developed a different physiological account of hypnotic phenomena.

Another peer-reviewed historical article on PMC makes the distinction even more directly: it says that what later came to be called hypnotism was only part of Mesmer’s treatments, and that later physicians tried to separate hypnotism from its "semi-occult mesmerist past." A 2025 clinical review likewise distinguishes the timeline: Mesmer first proposed animal magnetism, and only later did James Braid introduce the term "hypnosis."

So the historically accurate relationship is: animal magnetism/mesmerism was an antecedent or precursor to hypnosis, not simply “what we now call hypnosis.”