Originally Posted by SoundEdit
To the contrary, the burden of proof is on the positive claimant.
It seems you didn't read my explanations, but let me give some extra feedback if you are willing to read. My arguing is related to your claim above being all too categorical, as if always
and in absolutely all cases
the burden of proof is on the positive claimant. This I'm saying is not always
the case. There are exceptions. I agree in specific contexts the burden of proof is on the claimant, in general scientific argumentation, presentation of new theories etc, it is. But in certain circumstances and contexts it is not. For instance, in a criminal court the burden of proof is always on the prosecutor (in some countries at least). The defendant can say "I am innocent", and he doesn't have the burden of proof on that positive claim. It is on the prosecutor side to support an opposing positive claim
: that the defendant is guilty. Even outside courts of criminal law, not in all cases the burden of proof is on the person who makes a claim. For example, just because the claimant lacks interest in having his claim accepted by the challenger, then he ignores the argumentative obligation to support his claim. Let the challenger find out on his own if he cares to do so. Otherwise, the challenger might as well reject the claim, and the claimant wouldn't care, because he stopped advocating that claim for acceptance by that challenger. That was my point.
The latter situation happens even in scientific contexts. Supporters of opposing theories bring their arguments forth, the opposing arguments collide, each side attacks the opponent's arguments and premises, and some times they don't reach agreement. Each side remains seeing stronger support on their side, and remains advocating it. This happens even in papers in scientific journals over years. Two opposing (or alternative) theories remaining under consideration. Agreement is not reached, so they put on hold the argumentation, they stop trying to support their claims further, at least till more conclusive evidence is found. At least momentarily, in some way they agree to not care about the opponent not accepting their claims immediately. They stop that "obligation" to keep supporting their respective claims for the other to get convinced. If some guy out of context then meets one of those scientists and asks him for proof of his theory, that scientist might very well ignore completely the request. Let that guy on his own find out and go through all the arguments and battles that have already been held. He doesn't have to assume the responsibility to support his claims all the time for all requests that are presented to him.
So who has the burden of proof in practical terms may depend on context, motivation, circumstances, and history.