I am aware that there have been two wide spread movements to bring the Evangelical and Roman Catholic Churches closer together (ECT and ECT2). My question is this: What has changed in Roman Catholic doctrine since the Council of Trent when the split was fully made and the evangelical movement anathematized by Rome? Have all of the changes that have encouraged these movements been from the side of the Evangelicals?
It's not that doctrine has changed as much as the importance of the arguments. The Roman Catholic Church and many Evangelicals now agree that much of the arguments were semantic, and political and cultural opposition played a large role (especially ongoing political rivalries between France and Germany and the Turkish threat in the Mediterranean). So what has changed isn't really doctrine, but rather the importance of wording those doctrines in certain ways versus others.
It is actually Evangelicals who have changed their doctrines, which is the reason for the recent ecumenical successes. In fact, the Second Vatican Council's Decree on Ecumenism states that ecumenical activity cannot result in changing any aspect of the Catholic faith. For example, Post Conciliar Document Number 42 says that the purpose of ecumenism is to transform the thinking and behavior of non-Catholics so that eventually all Christians will be united in one Church. It states, "This unity, we believe, dwells in the Catholic Church." In other words, "unity" means that all Christians will become Roman Catholics.
The reality of it is that the Roman Catholic Church is engaging in ecumenical dialog with Protestants and Orthodox, calling them "separated brethren," and claiming to respect their beliefs. But at the same time, it still officially declares that they are heterodox because of these same beliefs. Some Catholics have expressed concern over this.
Several thoughts which came up immediately:
There are a number of changes which have come from both sides. On the one hand, the Church has had a decidedly different approach to the separated brethren over the past hundred years. We have come a long way from when the Pope declared the Anglican Holy Orders null and void (Apostolicae Curae). This was accelerated through VAII and by the 1980's it had gotten to the point where JPII allowed Catholics to worship at Protestant churches in 1983 (and the Sunday after the law changed, he preached at a Lutheran church).
As the nationalism of denominations has declined, so the scholastic cooperation has increased. The scholars who study the ancient documents couldn't care less who wrote a particular book, so long as they actually supported their thesis. This is why the New Jerome Bible Commentary includes several non-Catholic sources.
There is an increased eye for objectivity. I have one book dated to the first half of the 20th century which makes the statement, "unfortunately, it seems that the people who followed the apostles followed more the theology of James than the liberating theology of Paul." The implication: that the early Church documents are wrong and that this person knows better.
The documents from the Ancient Church are more available and less "augmented". When Protestantism first came on the scene there were something like 16 epistles of Ignatius of Antioch (we can now authenticate, at most, 7) and the TR version of the Bible was decidedly corrupt. This made it much easier to say that personal interpretation was paramount to actual Biblical literacy.
Finally, major enemies of the Church, like Jack Chick and Loraine Boettner, have either fallen out of favor or died in the past 20 years. It has gotten to the point where new denominations are no longer quite as concerned with attacking the Church as, say, in the 19th century.