We can look at the world, witnessing all of the diverse behaviors, rules, cultural artifacts, and morally salient emotions like empathy and disgust, and we can study how these things play out in human communities, both in our time and throughout history. We can examine all these phenomena in as nonjudgmental a way as possible and seek to understand them. We can understand them in evolutionary terms, and we can understand them in psychological and neurobiological terms, as they arise in the present. And we can call the resulting data and the entire effort a "science of morality". This would be a purely descriptive science of the sort that I hear Jonathan Haidt advocating. (Harris)

For most scientists, this project seems to exhaust all that legitimate points of contact between science and morality — that is, between science and judgments of good and evil and right and wrong. But I think there are two other projects that we could concern ourselves with, which are arguably more important.

The second project would be to actually get clearer about what we mean, and s hould mean, by the term "morality," Understanding how it relates to human well-being altogether, and to actually use this new discipline to think more intelligently about how to maximize human well-being. Of course, philosophers may think that this begs some of the important questions, and I'll get back to that. But I think this is a distinct project, and it's not purely descriptive. It's a normative project. The question is, how can we think about moral truth in the context of science?

The third project is a project of persuasion: How can we persuade all of the people who are committed to silly and harmful things in the name of "morality" to change their commitments, to have different goals in life, and to lead better lives? I think that this third project is actually the most important project facing humanity at this point in time. It subsumes everything else we could care about — from arresting climate change, to stopping nuclear proliferation, to curing cancer, to saving the whales. Any effort that requires that we collectively get our priorities straight and marshal massive commitments of time and resources would fall within the scope of this project. To build a viable global civilization we must begin to converge on the same economic, political, and environmental goals.

Obviously the project of moral persuasion is very difficult — but it strikes me as especially difficult if you can't figure out in what sense anyone could ever be right and wrong about questions of morality or about questions of human values. Understanding right and wrong in universal terms is Project Two, and that's what I'm focused on.

There are impediments to thinking about Project Two: the main one being that most right-thinking, well-educated, and well-intentioned people — certainly most scientists and public intellectuals, and I would guess, most journalists — have been convinced that something in the last 200 years of intellectual progress has made it impossible to actually speak about "moral truth." Not because human experience is so difficult to study or the brain too complex, but because there is thought to be no intellectual basis from which to say that anyone is ever right or wrong about questions of good and evil.

My aim is to undermine this assumption, which is now the received opinion in science and philosophy. I think it is based on several fallacies and double standards and, frankly, on some bad philosophy. The first thing I should point out is that, apart from being untrue, this view has consequences.

In 1947, when the United Nations was attempting to formulate a universal declaration of human rights, the American Anthropological Association stepped forward and said, it can't be done. This would be to merely foist one provincial notion of human rights on the rest of humanity. Any notion of human rights is the product of culture, and declaring a universal conception of human rights is an intellectually illegitimate thing to do. This was the best our social sciences could do with the crematory of Auschwitz still smoking.

But, of course, it has long been obvious that we need to converge, as a global civilization, in our beliefs about how we should treat one another. For this, we need some universal conception of right and wrong. So in addition to just not being true, I think skepticism about moral truth actually has consequences that we really should worry about.

Definitions matter. And in science we are always in the business of framing conversations and making definitions. There is nothing about this process that condemns us to epistemological relativism or that nullifies truth claims. We define "physics" as, loosely speaking, our best effort to understand the behavior of matter and energy in the universe. The discipline is defined with respect to the goal of understanding how matter behaves.

Of course, anyone is free to define "physics" in some other way. A Creationist physicist could come into the room and say, "Well, that's not my definition of physics. My physics is designed to match the Book of Genesis." But we are free to respond to such a person by saying, "You know, you really don't belong at this conference. That's not 'physics' as we are interested in it. You're using the word differently. You're not playing our language game." Such a gesture of exclusion is both legitimate and necessary. The fact that the discourse of physics is not sufficient to silence such a person, the fact that he cannot be brought into our conversation about physics, does not undermine physics as a domain of objective truth.

And indeed, illustrious documents of venerable antiquity, of both the Eastern and the Western Church, very forcibly testify that this doctrine of the Immaculate Conception of the most Blessed Virgin, which was daily more and more splendidly explained, stated and confirmed by the highest authority, teaching, zeal, knowledge, and wisdom of the Church, and which was disseminated among all peoples and nations of the Catholic world in a marvelous manner -- this doctrine always existed in the Church as a doctrine that has been received from our ancestors, and that has been stamped with the character of revealed doctrine.

The text in question is one mistakenly attributed to St. Augustine, published in PL 40, 1140-48. It has been studied by G. Quandrio, Il trattato "De Assumptione B. M. B." dello Pseudo-Agostino e il suo influsso nella teologia assunzionistica latina, Analecta Gregoriana 7 (Rome, 1951).

There seems no doubt that Augustine considered Mary's exemption from sin to be a great grace. But what sins does he mean? Undoubtedly he excludes any personal sin from Mary. Is it possible to hypothesize that Augustine also intended to exclude original sin? Some scholars think so and make him a forerunner of the doctrine of the Immaculate Conception. A full treatment of the question would call for a lengthy discussion. To us it seems safer to adopt the contrary position, which is held by many experts and appears more in accord with numerous Augustinian texts.

The eternal Word, therefore, was given to us by the hand of Mary, and of the substance of Mary He put on nature without the blemish of original sin, and this He did, because that conception was not of man, but made by the inspiration of the Holy Spirit. This indeed was not so in Mary, because she did not proceed from the mass of Adam by the operation of the Holy Spirit, but of man. And because that whole mass was corrupt, her soul could not be infused but into corrupt nature, nor could she be purified but by the grace of the Holy Spirit, of which grace indeed, a susceptible body is not the subject, but a rational or intellectual spirit, and therefore Mary could not be purified of that blemish, till after her soul was infused into her body, which in truth was so done out of reverence for the Divine treasure, which was destined to be placed in that vessel. For as a furnace consumes a drop of water in a moment of time, so does the Holy Spirit the blemish of original sin: for after her conception she was immediately made clean of that sin by the grace of the Holy Spirit, and was endowed with great grace. Thou knowest, O Lord, that this is the truth.

It is the truth, that I was conceived without original sin, and not in sin.