The debate over Evolution, Creation and Adam and Eve is one of my least favorite topics.  That’s because I’ve accepted the theory of evolution ever since fourth grade, when it was first explained to me in science class by a Dominican nun.

As a result, debating evolution feels a lot like debating the Pythagorean theorem: It’s something I studied 40 years ago… long ago accepted… but makes my head hurt even thinking about.

This is one of the many differences between Catholics and Protestants, I’ve found.  Catholics rarely if ever think about evolution.  For Protestants, it’s one of their favorite subjects, a principal “litmus test” for theological orthodoxy in many churches.

It took the agnostic New Testament scholar Bart Ehrmann nearly 20 years of rigorous graduate education before he could finally come to accept what I learned in fourth grade:  that human beings have existed on the earth for hundreds of thousands of years… and their physical bodies likely developed out of more primitive animal forms.

When I was in high school, one of my Jesuit teachers showed me a copy of Pope Pius XII’s encyclical Humani generis in which the pope explained that “the doctrine of evolution, insofar as it inquiries into the origin of the human body as coming from pre-existent and living matter” is not incompatible with Christian faith as revealed in the Biblical texts.  Here is the key section (36):

For these reasons the Teaching Authority of the Church does not forbid that, in conformity with the present state of human sciences and sacred theology, research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter – for the Catholic faith obliges us to hold that souls are immediately created by God. However, this must be done in such a way that the reasons for both opinions, that is, those favorable and those unfavorable to evolution, be weighed and judged with the necessary seriousness, moderation and measure, and provided that all are prepared to submit to the judgment of the Church, to whom Christ has given the mission of interpreting authentically the Sacred Scriptures and of defending the dogmas of faith.

The key point for Catholics, the pope explained, is that human beings are all descended from a real, historical, single human pair (called in Hebrew ha-adam and Hava, Adam and Eve), however they may be conceived.

Theologically, this belief is known as monogenism, the view that human beings are descended from a single couple.

Ironically enough, scientists in the 1950s were leaning toward another viewpoint, that of polygenism, the belief that the human race developed from many different independent groups.  I have to admit, to my teenage mind, the theory of polygenism seemed much more plausible.  After all, doesn’t it make more sense that there were many different groups of primates all over the world and humans “evolved” independently from those groups?

Nevertheless, I’ve never had any problem believing in both the Genesis account of creation and in various scientific theories of evolution.  Neither of the twin fundamentalisms in this debate — that of some evangelical Protestants or that of atheist scientists like Richard Dawkins — appealed to me.

Pope Pius XII’s explanation made more sense to me:  The first 11 chapters of Genesis, the pope explained, do not conform “to the historical method used by the best Greek and Latin writers or by competent authors of our time” yet constitutes history in “a true sense.”

The inspired text, he added, “in simple and metaphorical language adapted to the mentality of a people but little cultured, both state the principal truths which are fundamental for our salvation, and also give a popular description of the origin of the human race and the chosen people.”

Precisely:  Genesis is …

(1) a “popular description of the origin of the human race,” using

(2) “simple and metaphorical language,” that nevertheless contains

(3) “principal truths which are fundamental for our salvation.”