This isn't really an argument from utility, but you've gotta like the spin-offs.
Many people know we owe a kind-hearted Shaker for the circular saw; from the room where she ran a spinning wheel, she could see men using a pitsaw -- hard, tedious work and a face-full of sawdust for the low man on the saw. She looked back at her spinning wheel and something clicked. This is far from the only invention credited to a Shaker; they even dreamed up the common clothespin.
They're not the only ones. There was a bunch of jazz-playing, baseball-playing (and 'stonishing good at both) religious folks living in communes up in Michigan -- there's a few still there -- without whom you might not have canned grape juice, freeze-dried foods or mechanical pinsetters for bowling, not to mention those nice white fillings in your teeth. And you've probably never heard of them...unless you're old enough to have gone to their amusement park! They're the House of David, bearded, long-haired, vegetarian, celibate and by every account, a pretty fine bunch of folks.
See, what my neighbor believes about the Infinite does not usually impact me, if he's peaceable about it; but the things he does in this life -- what he dreams, what he builds, how he treats others, those things do affect me; if he comes up with an improved bearing metal, if he plays baseball well enough to give the Kansas City Monarchs* a good game or is a talented artist who writes stirring op-eds encouraging decent and upstanding behavior, that does matter. If his faith leads him in those directions, all the better.
This isn't meant as a utilitarian argument; the best possible defense of freedom of conscience in matters of religion is that it's not only repugnant to attempt to police the contents of people's minds, it is ultimately impossible. It is a nice side-effect that, if you leave people's beliefs be, there's often a free prize inside.
* Which is how I stumbled across House of David. Following links from the Satchel Paige bio, I realized the Monarchs had an enviable record; looked them up and found mention of their barnstorming with the House of David playing integrated baseball back before the Major Leagues wised up. That seemed worth following up, but who'd'a thunk.
3 months ago