Judith Jarvis Thomson's latest essay on abortion is a futile attempt to resolve the nation's most divisive issue by allocating the burden of proof to the other side. She says we are unsure about the status of the fetus, so we should err on the side of liberty. The Pope is not unsure about the status of the fetus, but he says with equal logic that even if we were unsure, we should err on the side of life.

Professor Thomson's famous article about the violinist addressed the merits in an important way. Her recent article about burden of proof does not.

The rival claims about burden of proof simply restate the rival values that underlie the whole bitter dispute. Perhaps some of the undecided or deeply ambivalent will take comfort from burden-of-proof arguments, but it is absurd for anyone on either side to think that they will make substantial progress by allocating the burden of proof, or by any other technical argument.

This is an issue on which honorable people fundamentally disagree and will never be persuaded. The issue will come to rest only when a large majority is persuaded to one position or the other, or to some compromise, and when that majority is large enough and strong enough to establish a political equilibrium that can withstand the minority's bitter dissent. The path to that equilibium is far from clear, but surely it requires arguments on the merits, and not arguments that purport to avoid deciding the ultimate issue.

Professor Thomson's famous article about the violinist addressed the merits in an important way. Her recent article about burden of proof does not.