The burden of proof in arguments

[Madame Adequate]

There is no such thing as proof for a negative claim. What's the only "proof" that unicorns don't exist? The fact that there's no evidence that they do. The only thing that can be pointed to as proof of a negative is absence of evidence for the positive claim.

So you're mostly right, but the person asserting the positive claim has the burden of proof. Period.

I suppose where he is coming from with this is if you are having a discussion about... I don't know, the effects of gun control? If I provide evidence that gun control reduces crime, you might still produce a study which demonstrates different consequences.

Actually no, I suppose both claims there are positive ones and so proof is required by either side anyway...