ting can be a symptom, e.g., if the siblings do it their free will, if they feel forced to...).
In my opinion it is ethically critical to prescribe any behavior to a person if not to cure a sickness. Who am I, the therapist, to do so? Fighting, in most cases, is just a behavior, as you write.
Although not being a case for PI the example can serve for showing the opposite approach of the two techniques.
Symptom prescription deals with the so far used coping strategy: the siblings should fight, what they did before. The have no fear of fighting, they just don`t like it in a way (what is similar to the bacteriophobia: there the patient has no fear from handwashing, but from the bacteria). Symptom prescription is prescribing a behavior, hoping, that the so far used strategy is loosing its uneasiness (because it is socially allowed from now on, or because it becomes even ridiculous by doing it voluntarily etc.).
Whereas Paraoxical Intention is of the symptom, PI lends no attention to the symptom itself, by letting it aside (in a "de-reflecting" manner). PI attacks the cause of the (neurotic) because the therapist knows, that this cause is not an adequate cause for such a fear, since it is the fear of the fear, which makes the symptom. Therefore the therapist may remain confident because the catastrophe cannot happen, "the world will not break down". That is the reason why he can speak so humoristically about the fear, being vicariously relieved.
In our case, the siblings would have to say they are fighting. They would state, e.g., that they are fighting for really nothing, for things that stand not for fighting.
This is the visible "about" of their fighting (there is no fighting without an "about" - the "about" is the "object", the fighting is the behavior/symtom). PI would aim at the "abouts", exaggerating them: "All these nothings, I am fighting for, are the most precious things I have on earth, and I would not hesitate and go and die for them..." Thus it becomes (slowly) clear to the client, that he has no real reason for fighting, just because it is not worthy to do so (he is getting a new "hierarchy of values", as we say) - or (in this case), he becomes clear, that he is fighting for a so far unknown, real value.
What I wanted to show: PI aims the underlying grounds, the causes. It is an attacking technique leading to a new of the intentional goals (the "what for" I am acting = behaving). PI does not prescribe any behavior (does not intervene on an ethical level), but brings about the courage with the aim that the patient/client starts to check personally what`s the real matter with this world. PI is a way of questionning the phenomenon.
Alfried A. Längle, M.D., Ph.D.
(President of the Society)