What do we really mean by a burden of proof? Vinny gets right to the crux of the biscuit:
"Burden of proof" assertions between atheists and theists often boil down to "I can offer no positive proof for my position, but I am going to declare myself the winner anyway since you cannot offer any for yours either."He's descriptively correct, but I think he underestimates the power of this position. A burden of proof requires one party in a controversy to actively do something positive; if that party fails to do what's required, her opponent need do nothing to actually win.
Note that the quoted description is very different from Vinny's other characterization: a burden of proof "is sort of like the 'tie goes to the runner' rule we used as kids playing baseball." But in this situation, both parties have to do something active to succeed; there is no "default" if neither party actively performs the required task: the runner must actively run from home plate to first base, and the defense must actively move the ball to first base. Furthermore, given enough time, neither party will fail. If the runner stands still, he will eventually be put out. If the shortstop holds the ball, the runner will eventually be safe.
There are situations where it seems important to asymmetrically set one party a task she can fail to perform, and require a task from her opponent only if she succeeds. To carry on the baseball allegory*, the pitcher has an asymmetric task of throwing a strike: he can fail at that task (since he gets only one try), and if he does fail, the batter need not do anything to be safe. If the pitcher throws a strike, he has successfully transferred a metaphorical "burden of proof" to the batter: the batter must make contact with the ball: if he fails to do so, the defense need not do anything for the batter to be out.
*Using grossly oversimplified rules of baseball.
So why do we need the concept of "burden of proof" in argument? Are arguments more like the metaphorical symmetric situation, where the "burden of proof" is applicable only if both parties perform their active tasks exactly equally? Or are there some situations where we might say that one party has a requirement to actively fulfill some requirement, achieve some task; a good try doesn't count if the requirement is not actually fulfilled.
In criminal* cases, however, the prosecution has the initial burden of proof, a burden that's different from the "beyond a reasonable doubt" standard of proof she must eventually achieve. The prosecution must actively introduce some evidence establishing the elements of the crime. If she fails to do so, the defense can effectively rest without introducing additional evidence, and in closing remark only on the prosecutor's failure to meet her burden of introducing some evidence.
*As best I understand with my Law & Order J.D., which focuses on criminal procedure and law.
If, however, the prosecutor does introduce some evidence, the defense now has a burden to cast reasonable doubt on that evidence (or to raise an affirmative defense); if the defense fails to do so, a conviction will probably result* without further argument by the prosecution. What we see are shifting burdens of proof to achieve a standard of proof.
*Unless as in Twelve Angry Men the jury does the defense attorney's work for him.
The notion of "innocent until proven guilty" establishes neither a burden nor a standard of proof: it only specifies what happens if the standard is not met by the process of shifting burdens of proof.
Given this notion of what a burden of proof is, I'll talk about its applicability in philosophy in