---
title: "Jules Liégeois"
chunk: 4/7
source: "https://en.wikipedia.org/wiki/Jules_Liégeois"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:27:26.427074+00:00"
instance: "kb-cron"
---

=== "Waking" and "hypnotic" suggestion ===
Although Liégeois' initial experiments reflected his academic interest in the legal parallels between hypnotism and natural/spontaneous (i.e., rather than "mesmeric" or "artificially induced") somnambulism, his major work over an extended period involved a thorough investigation into the principles and practices responsible for a far wider range of applications of "suggestion" — involving both 'waking' suggestion and 'hypnotic' suggestion — than their medical and/or therapeutic applications alone.
In particular, given his forensic interest in the effects of "suggestion" and their significance in relation to issues of posthypnotic amnesia, and the personal responsibility/culpability for the phenomena produced by "suggestion", he was also deeply interested in the nature, form, and content of the "suggestions" made. Driven by his concern with the philosophical and forensic (rather than therapeutic) aspects of hypnotism and hypnotic suggestion, Liégeois asserted, along with Charcot's associate Pierre Janet (1920, pp.284–285), that  the critical feature of the subject-operator interaction was not the operator's making of the "suggestion", but, instead, was the subject's taking of the "suggestion" made by the operator. As Yeates (2016a) observed, in the same way that "one is only a "hypnotist" if one induces "hypnotism" ... an idea is only a "suggestion" if it "suggests" something"(p. 35); and as Titchener (1910, p 450) noted, without knowing the subsequent response to its presentation, there is no objective a priori difference between a "suggestive idea" and any other idea; and, from this, Titchener argued, "suggestion" can not be a (before the yet-to-be performed event) "descriptive" term, but is only a (subsequent to the reactive event's occurrence) "explanatory" term.
Among the wide range of experiments Liégeois conducted, his subjects displayed responses to suggestions made at a distance in time (1886e) and at a distance in space (1886b, 1886c). He confirmed (1886e) the existence of what Berhheim described as les suggestions post hypnotiques à longue échéance ('post-hypnotic suggestions to be realised after a long interval'), when one of his subjects demonstrated a suggested result precisely 365 days (as demanded by Liégeois) after the relevant hypnotic suggestion had been delivered. He also demonstrated that subjects (i) could be hypnotised, and (ii) would respond to suggestions delivered to them over the telephone: and, in his report (1886b, p. 142; 1886c, p. 24), Liégeois also supposed that a similar outcome might be achieved by a phonograph recording.

=== Hallucinations ===
The work of French alienist Jacques-Joseph Moreau's (1845) Du Hachisch et de l'aliénation mentale — which spoke of the hallucinations induced by drugs (e.g., opium, hashish) in otherwise "normal" people — had begun to shift disciplinary consciousness away from the view that, "because hallucination was a verifiable feature of the behaviour of the insane, the phenomenon must in itself be pathological" (Finn, 2017, p. 22), towards one that accepted that a capacity to experience hallucination was a feature of an entirely normal "existence intérieure" ('inner/subjective existence') and an entirely normal "vie intrà-cérébrale" ('intracerebral life'):

"The hallucination ... encompasses all of the faculties of the mind; its only limits are those that nature has placed upon the activity of mental functions. In other words, all mental abilities can be hallucinated, and not just certain abilities, such as those connected with the perception, for example, of sounds or images." — Jacques-Joseph Moreau (1845).
Liégeois devoted an entire chapter of his 1889 work to the experiences of himself and others in relation to those hallucinations induced by hypnotic suggestion; namely, both:

(a) "hallucinations positives", perception of some thing as being present in the absence of any related external stimulus; and
(b) "hallucinations négatives", perception of some thing as absent in the actual presence of a specific, related external stimulus: i.e., the rationale behind the modern processes of hypnotic pain management.

== Liégeois, hypnotism and crime ==
As an academic and jurist Liégeois was interested in "the subject of personality modification and its implications in law" (Marchetti, 2015, p. 81) and, in particular, the legal questions raised in relation to "culpability", for instance, in the case of M. Emile X—, as it had been observed by Adrien Proust (father of Marcel Proust) the Inspector-General of the French Government Sanitary Service, and had been reported in the French press, "as to the possibility of anyone exercising such an influence over another person as to make him or her irresponsible for the acts committed under that influence, even though those acts may be crimes". Liégeois was especially interested in the extent to which it was possible that (otherwise innocent) subjects could be induced, by means of hypnotic suggestion, to commit crimes, thefts, and even murders. Gauld (1992, p.497) characterizes these events as "hypnotic crimes": namely, crimes wherein the hypnotic subject was both the "victim" and the "agent" of the crime — with the suggestion-delivering operator, rather than the suggestion-complying subject, being the actual "criminal". As Harris (1985,  p.  486) notes, this view produced "unresolved tensions and ambiguities", because the Nancy School, "on the one hand [was] arguing that hypnotism had enormous potential to ameliorate previously intractable conditions, and on the other [was] regarding it as the possible motor for the committal of unspeakable crimes".