The passage cuts against every fantasy of the analyst as unmoved mover — the technically skilled professional who reads the patient's material from a safe remove. Jung's insistence that influence flows in both directions is not a therapeutic technique; it is an observation about how psychic contact actually works. If the analyst is sealed off, nothing real happens. The patient's unconscious reads the seal and speaks to it, or falls silent altogether.

What this asks of the analyst is not more empathy in the conventional sense, but a willingness to be disturbed — to notice what the patient's material begins to do inside the analyst's own body, fantasy life, irritability, dreaming. Countertransference is not a contamination to be managed; it is data the analyst cannot generate any other way. The difficulty is that most training instills something closer to the opposite habit: containment as the primary value, the therapist's interiority as a problem to be regulated rather than a medium to be read.

Jung named this mutual susceptibility because he had felt it himself, in the wreckage of his relationship with Freud and in the analysis of patients who changed him in ways no theory had predicted. The influence he describes is not warm attunement. It is closer to contagion — which is not a criticism, only the honest word for what passes between two people when the wall comes down.