I adopt a scientific approach, an objective point of view. I don’t suppose the existence of anyone.

My question is:

What is necessary so that the pain (1) appears (exists)?

(1) The initial question is in fact more general: what is necessary so that the knowledge of things’ existence appears? The pain’s sensation is here an example.

At least an alive being “struck” by a traumatising event. Of course. 

But is it sufficient?

Obviously… NO.

A famous French philosopher, Sir La Palisse , said indeed: for each one among us, the pain is produced only by one body: his body.

In fact, a body in life (and in good health) struck is NOT sufficient to make “this certainty to have badly” appear. So an other thing is necessary (elementary logic). Yes, but WHAT? 

A concrete, objective and clear answer is required. To retort “the spirit!” or “the conscience” is insufficient because the spirit (or conscience) is supposed being produced by the body (which means clearly that if a body exists, the spirit or the conscience exists). The answers calling upon God, transcendent spirit, are not accepted (too much easy, it is my answer!).

The same thing... in Deutsch.