"The very fact that we all know the age is an arbitrary boundary that could be set in different places shows this."

BS.

Despite proofs that the very brain maturity which "justifies" nullification doesn't finish until 25, we will never see it set at 25 and you know it.

The 24 year old might not have a brain "mature enough" to choose wisely, but they have too much physical clout, economic clout and political clout for all that lofty talk about "maturity" and "reason" to matter.

Its always been about picking on the weaker.

In the modern era women and minorities can no longer be subjugated by the State and made weaker. So children are the last bastion for bullies.

As with the science of race, gender, and sexual orientation; the science of age keeps moving further and further away from the illiterate premises that conflated science with the bias of the bully. So instead of settling on the "proven" it is the arbitrary which is held up as a valid goal.

"The argument for it that I accept is a pragmatic one."

"Pragmatic" is just the weasel-word for "what I can get away with." Slavery was "pragmatic" in its day.

That the argument you accept happens to be the one you've been force fed tells me that reasoning doesn't play into it at all. Had you been born in an era when the magic age was 21, you would be arguing against 18. And had you been born in an era where it was 15, you'd be arguing against 13.

Thank you for reminding us that "all is for the best in the best of all possible worlds," Dr. Pangloss.

Dante