occasionally something similar can happen to civilized man, only he does not describe it as ‘loss of soul’ but as an ‘abaissement du niveau mental,’ Janet’s apt term for this phenomenon. It is a slackening of the tensity of consciousness
Jung directly equates the primitive ‘loss of soul’ with Janet’s abaissement du niveau mental, defining it as a slackening of conscious tensity and establishing its clinical and anthropological scope.
, The Archetypes and the Collective Unconscious, 1959thesis