A few years ago, on a windy and cold January day in Washington, D.C., I stood in the snow as five or six Catholic bishops greeted the people gathered for the annual March for Life.

None of them said very much. They were, after all, only a few of the many people to be introduced before the march began.

They simply affirmed their love for the unborn and their support for laws that would protect them from harm.

I was then an Episcopalian, and served on the board of the Episcopal pro-life ministry NOEL. There were no Episcopal bishops in Washington that day and very few Episcopal priests, and my eyes filled with tears as the Catholic bishops spoke. They did not say much, but it was enough for me that they were there.

Last year, at the Easter Vigil, my family and I were received into the Catholic Church. A person becomes a Catholic for a lot of reasons, but one reason that I said “I believe all that the Catholic Church teaches” was the sight of those bishops standing for the unborn, and all their witness told me about the life and faith of the Catholic Church.

Among the most important things it told me was that the Catholic Church thought clearly. She had that mixture of clarity and confidence that I saw as a hint of the divine, in part because the mixture was so uncommon. In the bishops on the platform, I saw the heart of the Catholic Church, but I also saw her mind.

By saying that the Church thought clearly I mean that she, almost alone among human institutions, began with the fact that the unborn child is a human being and drew the conclusion that he or she must be protected from harm. It seems an obvious thing to think, but an amazing number of intelligent people do not think it.

As an activist, I had dealt for years with pro-choice activists, and found that they make two mistakes. First, some will tell you that the unborn child is not a human being. The closer he is to conception the more likely they are to say this. But they cannot produce any good reason for believing that a creature with the human genetic code, who will develop into a creature whose humanity is obvious to plain sight, is not human.

Here, I saw, was the truth about human life recognized and proclaimed.

Second, many will say that the unborn child is a human being and then say that he can be killed if his mother does not want him. But they cannot produce any good reason for believing that one type of human being can be killed at someone else's instructions while everyone else must be protected. (The odds are that these same people oppose capital punishment, and think it very bad to kill killers.)

Some of these will try to produce a philosophical explanation for letting people kill other people at will. They will tell you — I got a letter to this effect as I was writing this — that the unborn child is human but not a person. Having said this, with rare exceptions these people will not follow their logic to the end and argue for killing born babies who do not qualify as persons under their criteria.

Some people will try to cheat. They throw up their hands and declare that the decision to abort a child is a tragedy, forced upon us by the irreconcilable needs of the mother and the child. But they argue no more rationally than the others. They will not give you any way of deciding why this is a tragic situation that justifies one killing the two, while a child's need to remove his parents to get his inheritance is not.

In other words, you rarely find in the pro-choice position a truly rational argument for abortion, one that the pro-choicers are willing to work all the way through. Their reasoning either depends on an axiom they cannot defend or does not draw the conclusions their assumptions require.

In the Catholic faith I found a truly rational argument. The unborn baby is a human being and therefore has all the rights of a human being, among which is the right not to be killed. One may disagree with the argument, but it makes sense in a way the pro-choicers’ arguments do not.

I became a Catholic in part because in the Church I found the most reasonable people. Here, I saw, was the truth recognized and proclaimed.

I had tears in my eyes when we were received at the Easter Vigil. They were, in a way, the same tears I had shed six years before, standing in the snow listening to the Catholic bishops tell the marchers that they stood for the unborn.

David Mills is the author ofKnowing the Real Jesus (Servant/Charis) and a senior editor ofTouchstone magazine (http://www.touchstonemag.com).