Are Roman Catholic baptisms valid? This question has been debated from the time of the Reformers till the modern day. Assuming that the Roman Catholic Church is a false church, and the pope an antichrist who denies the Gospel, can we accept the Roman Catholic sacrament of baptism, which is not only corrupt because of Rome being a false church, but it is also corrupt because it is a magical ceremony working "grace" ex opere operato in the one being baptized?
Historically, those who fully reject Roman Catholic baptisms and all forms of pedobaptisms in the 16th century were the Anabaptists. Within Presbyterian and Reformed circles, the general consensus then was to accept Roman baptisms. In the 19th century however, a group led by Southern Presbyterian J.H. Thornwell took the position that Roman baptisms are invalid and should not be accepted. Opposing him was the giant Charles Hodge but to little avail as the General Assembly at that time ruled in Thornwell's favor. Of course, with the rot of Liberalism in the late 19th/ early 20th century, this ruling has been all but erased in the practice of the PCUSA. The key thing to note is that American Presbyterianism has at one time decided that Roman baptisms are invalid.
Much discussion about the validity or invalidity or Roman baptisms center over the criteria for valid baptisms, of which the major ones are (1) being done in the Triune name, (2) being done by a legitimately ordained minister, and (3) being done with water. Historical issues that have to be taken into account by those who claim to be part of the universal church are the Donatist controversy and the Reformers' rejection of the Anabaptist rejection of Roman baptisms. The Donatists linked the validity of one's baptisms to the holiness of the minister, thus if the pastor apostatized, all baptisms did under him became invalid. More pertinent to our issue, the Anabaptists called the Roman church a false church, and also rejected the doctrine of pedobaptism, and thus they reject Roman baptisms altogether. With such an eerie similarity, doesn't it seem that to reject Roman baptism is to follow in the footsteps of the Anabaptists, and thus be at variance with the Reformed tradition?
After giving much thought to the issue throughout the years, I think what is missing in this entire discussion on Roman baptism is to frame the discussion in its historical context. The unspoken assumption we make in our reasoning is to think that the process of us questioning the validity of Roman baptism today is the same process the Reformers took in questioning the validity of Roman baptism. That however is not the case, for such an assumption neglects the historical contexts of our time, and the Reformers' era.
The Reformers' context
The first assumption we have to discard is to think of the Medieval Catholic Church as being the Roman Catholic Church. That is not the case. Secondly, we have to understand that the Reformers saw the Medieval Catholic Church as corrupt yet still a church. To them it was the only church they knew, and none of them had the initial intent to set up an alternate church. Even after Trent, the Roman Church was seen as corrupt and unreformed, not another religion altogether.
Perhaps an analogy would help us see what the Reformers saw. Imagine you were brought up in a Christian family (if you weren't) and grew up in the same church with your parents and grandparents, and all your Christian friends. But when you grew up, one day the elders decided that salvation is by faith plus one's faithfulness (works) as a loyal church member (Federal Vision). Only you and a few others protested that this was contrary to Scripture, while most of your family members and friends are not so much against you as much as they couldn't see the difference between the true Gospel, and the new (Federal Vision) "gospel." Believing that this error struck at the heart of the Gospel, you and a few others separated to form a new church body. Now the question then arises: Is your former church a true church? Not if it continues to hold to the Federal Vision heresy. But assuming you had some theological training and over time was called to be the pastor of that new non-FV church, would you accept the baptisms done at your former church? Presumably, you would. Would you accept any baptisms done after the FV church officially revised their Confession of Faith to be in line with the Joint Federal Vision Profession? That sounds like a thorny proposition to consider, I would guess.
What this analogy hopes to show, absent any knee-jerk reactions to Roman Catholicism, is to illustrate how the Reformers would have felt towards the Medieval Catholic Church as it slowly jettissoned the Gospel. The Reformers were looking at their former church apostatized, which is not our experience towards Roman Catholicism at all. History and real-life is messy, and the analogy is meant to show the messiness of apostasy and how ecclesiastically dealing with such a separation is not an easy thing to do. This analogy is also meant to show us how it is natural for the Reformers to accept the Medieval Catholic baptisms of their time, for these baptisms were done by the Church, which was the only legitimate Church prior to the Reformers. In fact, it would be shocking if the Reformers did not accept the baptisms of the Medieval Catholic Church, for it would signal that the Medieval Catholic Church was not just corrupt, but fully a false religious institution akin to paganism.
Our modern context
Over time, the Reformed churches and Rome have diverged more and more. While certainly they are and always will be those in the Reformed tradition who want to go back to the 16th and 17th centuries, hopefully they will not be the future of the Reformed churches. Regardless, Rome has moved even further away from her Medieval Catholic roots into full-blown apostasy. Name any modern heresy, and chances are some Roman theologian or movement has toyed around with it sometime or another.
The list of heresies Rome has embraced or toyed with go way beyond the pale of anything resembling Christianity. With her inclusivism and elevation of Mary to unofficial semi-divine status, Rome should be seen as being another religion altogether.
As opposed to the Reformers, none of us, even converts from Rome, have seen Rome as a church that was once orthodox in their lifetime, or even their grandparents' lifetimes. Most modern Roman Catholics are not even devoted to the church with fides implicita as most Medievalists are. Many have no qualms trying out other religions and their practices, something that would horrify Medieval Catholics.
Judging by Rome's heresies, it should be a no-brainer why we should reject the validity of Roman Catholic baptisms today. We are after all dealing with another religion altogether, not a church that was once sound (unless one goes back 400+ years). And although there is surface similarity with the Anabaptists, the Anabaptists' reason for rejecting Medieval Catholic baptism, taking into account the historical context, was for the complete revolution of the Christian faith. Our reason for rejecting modern Roman Catholic baptisms however is not about revolutionizing the Christian faith, but about rejecting the magical ceremonies of a false religion.
Historically, therefore, we can agree with the Reformers on the validity of Medieval Catholic baptisms in their time, while rejecting the validity of Roman baptisms in the modern era. The Reformed churches have generally accepted Roman baptisms, but they should in my opinion rethink the issue afresh instead of defaulting to the historical position. That position was valid then, but it shouldn't be valid now. After all, I am writing this in the 21st century, almost five centuries from the start of the Reformation.