There’s a short but interesting summary of a survey about the effects of knowledge on the opinions that men and women hold about the moral legitimacy of some controversial medical/scientific procedures such as the use of various sorts of stem-cells. See Scientific Information Largely Ignored When Forming Opinions About Stem Cell Research. In a nutshell, those who hold prior moral beliefs about such matters, usually because of more basic religious beliefs, don’t change their opinions about, say, embryonic stem-cell usage if new research results indicate embryonic stem-cells can be used to cure some terrible disease. It’s hardly surprising, at least to me, that those who think the Ten Commandments and the Sermon on the Mount are binding will not change their opinions on allowable human actions because of individual fragments of empirical knowledge, even when those fragments speak of cures for cancers or neuro-muscular diseases. After all, we don’t look at the evidence of success for the relatively homogeneous population of Japan and decide that maybe ethnic cleansing of alien populations can be a good thing. If something is morally wrong, alleged practical benefits have no effect on its moral status. But some don’t put such activities as harvesting of cells from aborted fetuses or from eggs fertilized in the laboratory in the same category of moral wrong-doing as genocide. And I don’t really wish to start out assuming that those modern medical techniques are in that same category. I just wished to make the point that a belief that something is absolutely wrong isn’t going to be subject to any change from most sorts of empirical evidence.
I’d also like to make the point that even natural moral reasoning not allied to some sort of absolute beliefs, perhaps revelations from the Bible, should still have a core of beliefs which don’t change readily. I’ll step outside of moral reasoning to speak of a field of study often considered a high point of human rationality — physics. As evidence piled up against some of the problems of so-called Newtonian physics, physicists kept patching up an increasingly baroque structure of thought rather than throwing aside increasingly implausible basic beliefs in response to the mounting piles of inconvenient empirical facts. A discussion as to whether they should have changed before Einstein forced the issue is beyond the scope of this posting, and probably beyond my knowledge of the situation, but the point is that you don’t dynamite the foundation when you realize the plumbing to the bathroom is bad. When you realize all the plumbing is bad and the electrical system is in bad shape and then you discover cracks in the foundation, you might plan on detonation even if you still have to remain in the building so long as it’s not in immediate danger of falling. At that point, you begin to think through a better design for a new structure and you might move fast to excavate and build.
In many of my writings, I’ve criticized my fellow Christians for not seeing that many of their moral beliefs and all of their ways of expressing moral beliefs should reflect the nature of a human animal and also the nature of our universe which is the only phase of Creation which we can experience and the only phase we can explore. Most human beings throughout history have reasoned according to their understanding of their own nature and also their understanding of their own environments and any other environments of which they’re aware. Human beings in all ages start out with a great deal of knowledge about appropriate behavior as understood in their families and neighborhoods and places of worship. In the modern world, even casual viewers of television documentaries often have acquired lots of more or less organized facts about bones dug out of the sands of Africa and the customs of tribes in Australia and oil-rich princes in the Near East. It doesn’t matter if a modern human being tries to consciously form his moral beliefs or if they come to him during his dreams after watching a television documentary about the evolution of the human race or about the development of human civilization. Unless that man is a new Socrates, he won’t be capable of the sustained attention to reality and the equally sustained lines of thought that can lead to the development of a set of rational moral beliefs. Such a rational system of beliefs would be stable enough that it would take a lot of new empirical knowledge and a large speculative effort to bring about significant changes. But few have any such rational system of moral beliefs as they have drifted away or even run away from the beliefs of their ancestors. Many just pick up beliefs here and there as if they were collecting shells on the beach.
The idea of forming a moral system which accounts for the actual nature of evolved human beings and their world is hardly new nor is it alien to Christian thought. In the 13th century, St. Thomas Aquinas taught us that we’re ‘mostly’ physical creatures. He felt forced to conjecture a strange and non-human ‘soul’ that would survive the death of the human body but it was no more than an entity which does abstract thinking. Teaching we have souls separable from our bodies was his biggest mistake in matters of human moral nature, but his views on human moral nature were otherwise so solid by the high standards of modern empirical knowledge that one of the most highly regarded brain scientists of our era has endorsed those Thomistic teachings. See What is Mind: Pragmatism and Thomistic Existentialism and succeeding parts in that series for my review of Walter J. Freeman’s How Brains Make Up Their Minds. Professor Freeman gives a remarkably clear and concise description of Thomistic teaching on the ‘intentionality’ of human moral nature. (A warning, ‘intentionality’ in the Thomistic sense has nothing to do with motivation or setting goals and all to do with your movement along a certain path. If you drink excessively and get behind the wheel of a car, you’re acting as if to kill another human being. In terms of Thomistic moral teachings, you intend to kill.)
Human reason and knowledge of human nature, along also with knowledge of other creatures, tells us that human beings are a rather unique species of ape, but such true natural-law reasoning doesn’t justify the belief in the absolute value of even obviously human creatures let alone masses of cells in a petri dish or young embryonic growths in the womb. Reasoning from the facts of nature also tells us that it’s appropriate, pretty much by definition, for the members of a social species to place high value on the lives of others in their species, but not absolute value. In fact, wolves seem to be far more reluctant than human beings to kill members of their own species but few would see any possibilities of absolute truths coming from a deeper understanding of the moral nature of wolves.
It was the adoption of human beings as the brethren of Christ which gave human life some sort of absolute value. See Why are Human Beings of Greater Worth than Chimpanzees or Rattlesnakes for a discussion of this view of matters. I’ll speculate that this is the insight underlying the denial of the concept of natural moral law by John Howard Yoder and some other theologians. They’re right to this extent: it’s impossible to derive the fullness of Christian moral beliefs from the natural world because that fullness is based upon a freely made decision of God to incarnate His Son and the freely made decision of the Son to adopt all men as His brothers. Yet, the impossibity of deriving a free-will decision of God from nature doesn’t invalidate natural law which comes from human thinking and human common-sense reasoning.
In terms of any natural-law reasoning having much to do with nature as we know it, there’s no rational reason to believe human life to have absolute value in any meaningful sense. Christians have to realize they have no right to expect others to recognize truths which depend upon the revelation Who is Jesus Christ. Christians should also work a little harder to clear up their own beliefs and to recognize that they do have two sources for their system of moral beliefs: nature and Holy Scripture. We should respect those who haven’t accepted the Good News and the light yokes of Christ. If we wish others to accept the fullness of Christian morality, we should evangelize, should spread the Good News of Christ.
It’s also well within our duties as Christians to respectfully critique the moral positions which others might hold in good faith. We can and should also point out to our contemporaries that many of the ‘rights’ of ordinary human beings in recent centuries, much of the dignity we of the non-elite can claim, can’t really be justified without the belief that the Son of God became our brother, adopting us into His divinity. But even this development of a respect for human beings has to be seen and understood in natural terms, that is, in light of specific historical developments in particular societies which were at least Christ-soaked if not quite Christ-centered.