But, as for "the Church Penitent," where, precisely, might I read about the Catholic Church accepting its share of responsibility for the Reformation?

It is generally conceded that corruption in practice in the Catholic Church preceding the "Reformation" was a precipitating cause (not, however, to the extent that the schism is justified). Probably your best bet would be Pope John Paul II's encyclical Ut Unum Sint ("That They May be One") of 1995 (in my Orthodoxy & Ecumenism page). In it, he speaks, e.g., of "mutual misunderstandings and prejudices," "mutual forgiveness and reconciliation," (sec. 2), that "the Catholic Church acknowledges and confesses the weaknesses of her members" (sec. 3).

Karl Adam, in his The Roots of the Reformation (NY: Sheed & Ward, 1951), wrote:

It was night indeed in a great part of Christendom . . . [at] the end of the 15th century: amongst the common people, a fearful decline of true piety into religious materialism and morbid hysteria; amongst the clergy, both lower and higher, widespread worldliness and neglect of duty; and amongst the very Shepherds of the Church, demonic ambition and sacrilegious perversion of holy things. Both clergy and people must cry "mea culpa, mea maxima culpa"! (p.27)

Ditto for the St. Bartholomew's Day massacre.

Bertrand Conway, in his The Question Box (NY: Paulist Press, rev. ed., 1929, pp.199-200), writes:

The Popes had nothing to do with the massacre of St. Bartholomew's Day. Pius V did not plan the massacre with Catherine de Medicis, nor did he ever urge it upon the French court in any way; Gregory XIII never approved of the crime, but had a 'Te Deum' sung in Thanksgiving for the saving of the King and the royal court from death, according to advices sent him from the French court . . .

The massacre was a dastardly political crime of Catherine de Medicis, planned the evening before to avert the possible consequences of her attempted assassination of Coligny on August 22 [1572; the massacre occurred on the 24th]. Catherine had as much zeal for the Catholic religion as a modern bootlegger has for the cause of prohibition. She was a freethinker of the school of Machiavelli, bred in the worst traditions of the Italian tyrants, and ruling one of the most corrupt courts of Christendom . . .

No one holds tday that the massacre was premeditated . . . Not a bishop of France was present at the meeting that planned the massacre; no bishop ever gave it his approval. The Cardinal of Lorraine, who is often pictured blessing the daggers of the murderers of Paris, was actually in Rome when the massacre occurred . . .

That France lied to the Pope about the facts of the case, describing the massacre as the just punishment of conspirators, we know from the reports of the King's messenger, De Beauvillier, and from the letters of the French ambassador de Ferals, the Cardinal de Bourbon, and the Papal nuncio. Brantome, in his Memoirs, says that when the Pope learned the real facts, he shed bitter tears, and denounced the masacre 'as unlawful and forbidden by God.'

Yet another case of anti-Catholic propaganda overcoming the clear, verifiable historical facts of the matter.........but it assuredly works, so this has become a favorite, along with the Inquisition, Crusades, the bad popes, the Great Papal Schism, and Galileo........

Anti-semitism? I have studied the Crusades in depth. Any anti-semitism then was not the Church's fault.

Yes. But many Christians were guilty of it. So we apparently agree on this, and you know much more detail than I do, no doubt.

(For the Crusades, the best recent work is by a Catholic, Jonathan Riley-Smith). And in WWII? I think the Church got a bad rap on that. After all, Hitler also killed three million Polish Catholics (most, I believe, by the same methods, although I could be mistaken). I don't have an anti-semite bone in my body, but it has always bothered me "six million Jews"is always mentioned to the exclusion of these three million Poles.

Precisely. I agree 100%.