Let's say I claim to have invented an entirely new kind of artillery which can it take out protected targets by firing a projectile up in the air and then letting gravity bring it down. If you challenge my claim and we are talking about the part where the projectile goes up, the burden of proof is on me. If we are talking about the part where the projectile comes down the burden of proof is on you. I don't have to offer any evidence whatsoever to show that projectiles propelled into the air at less than escape velocity will return to earth.

Admittedly, that's a really contrived example but the basic principle does come up, often involving important questions.

Let's take masks and covid. If you accept that aerosol transmission is a significant factor in the spread of a disease, then I don't need to offer any proof that properly used face masks will reduce that transmission. It doesn't matter if there are no clinical or even observational studies to show this. Given aerosol transmission, it is almost impossible to come up with a viable scenario where wearing surgical masks will not help to some degree.

In general, productive arguments always follow the burden of proof. This applies as much to those making claims as to those challenging them.

Let's say you applied for a government contract to build a "hyperloop" (Musk's hyperloop wasn't a maglev train. It was also so unworkable that all "hyperloop" companies quietly scrapped the (Read more...)