My friend Ilya Somin has written a detailed critique of my doubts about the Protestant Reformation.  Here’s my reply.  He’s in blockquotes, I’m not.

1. Even had Luther stayed loyal to the Pope or
been quickly crushed, it is likely that other serious challenges to the
Catholic Church would have arisen in the 16th century. Some already had
previously (e.g. – the Hussites), and many people were dissatisfied with
the religious status quo for a variety of reasons.

I agree.  But the body count of the actual Reformation was so high, it’s hard to believe the alternative would have been worse.  And there’s at least a modest chance that the alternative challenge would have been relatively tolerant, secular, and humanist, instead of another variant on violent fundamentalism.

technological, social, and economic developments (e.g. – the printing
press, changing military technology, the start of the Renaissance) made
organized resistance to the Church easier than in the past. And once
resistance spread, it was likely to lead to extensive warfare, because
neither the rebels nor the Church were likely to compromise easily.

Plausible, but so are many more optimistic scenarios.  Precisely because the contemporary Catholic Church was “corrupt,” I say it was open to moderate reforms and a slow growth of pluralism.

2. Bryan asks whether the Church would have done better to try to crush
Lutheranism in its cradle. But the Pope (supported by the Holy Roman
Emperor) did in fact try hard to do just that, at least after 1521 or
so. Their efforts led to the German Wars of Religion, which lasted 30
years and took many lives (i.e. – exactly the result Bryan decries).
Perhaps the Pope and the Emperor would have been more successful had
they moved against Luther still earlier. But it’s far from clear.

I’m well-aware of the Church’s violent response – and freely concede that Catholics might have been able to avert bloodshed with tolerance.  That’s definitely what I would have done in their shoes.  But given Luther’s subsequent writings, I can’t give this upbeat scenario better than one-in-three odds.  Simply double-crossing Luther at the Diet of Worms seems like a better gambit for peace, though of course that could have ended in disaster, too.

3. The Thirty Years War – the bloodiest of the conflicts Bryan
attributes to the Reformation – was far more than just a Protestant vs.
Catholic conflict. Many of the combatants had other agendas they cared
about more. To take the most obvious example, Catholic France backed the
“Protestant” side in the conflict in Germany because Louis XIII and
Cardinal Richelieu were more interested in curbing the power of the Holy
Roman Emperor than in promoting the true faith. Whether the Reformation
(or religion generally) can reasonably be blamed for this war is at the
very least highly debatable.

All true, except for the last sentence.  The Reformation gave two rival movements compelling moral rationales for maximum savagery, and destabilized the entire continent.  You’d expect power-hungry pragmatists to take advantage of the chaos.  But without the Reformation, there would have been far less chaos to take advantage of.

4. Bryan ignores perhaps the
greatest benefit of the Reformation: the collapse of the Catholic
Church’s near monopoly over intellectual life in Western and Central
Europe. Most early Protestants were far from advocates of toleration.
But their rise inevitably led to greater intellectual pluralism in
Europe, which in turn helped give rise to the Enlightenment, modern
liberalism, and so on. Would the same thing have happened as quickly if
the Church had retained its dominant position? I am skeptical.

Over what time frame?  The Enlightenment started about two centuries after the Reformation.  Two centuries when – as Ilya points out – printing presses proliferated, drastically cutting the cost of spreading novel and diverse ideas.  The Catholic Church’s near-monopoly could easily have been peacefully eroded during those two centuries.  If this sounds like wishful thinking, look at what happened to European countries that remained solidly Catholic after the Reformation.  The Catholic Church peacefully became virtually powerless in every case.  Even Poland.