H. pylori is in the news again. It was back in the 1990's that the plucky bacterium, Helicobacter pylori which colonizes the inhospitably acidic mucous in the human stomach lining, first started making headlines as the real cause of peptic ulcers. Up until then the treatment had been bland diets and deep breathing, but now ulcer sufferers could look forward to real relief from a simple course of antibiotics. It was also implicated in some kinds of stomach cancer, so discovery and treatment was a remarkable achievement.
But the story didn't end there. Researchers have now discovered that H. pylori may also be involved in regulating stomach acidity in otherwise healthy humans. When its environment becomes too acid, the bacteria releases toxins that inflame the stomach lining, triggering a reduction in acid levels. For the last 50 years or so, increased sanitation and widespread use of antibiotics has reduced the overall infection rate for H. pylori, and we have also seen an attendant increase in acid reflux disease and esophageal cancer across the same populations. It's speculated that its decline may also be a factor in epidemic obesity because of its role in amplifying or suppressing the stomach's appetite signals.
So should we have it or not? Is it a good bacteria or a bad bacteria?
Of course it's not intrinsically good or bad -- there is nothing in its genome which encodes its moral value. As a bacteria it simply is. It exists; it has properties and qualities which can be measured and understood. It is a fact. To make a moral judgment about it requires evaluating it relative to a set of values. Values provide a rating system -- kind of a moral Siskel and Ebert -- that we can use to compare the facts about a situation or thing and determine if it's good or bad. From there it's a short step to normative ethics, where we decide what we should do based on the facts that confront us. The formula is: what is, measured by our values, determine what we ought to do. But where do our values come from?
The conventional answer is: Nowhere. Many traditions, from both right and left, insist that we cannot derive "ought" from "is". They believe that values, the system that takes us from observations to prescriptions, are arbitrary and are not subject to reason. The moral relativism of the postmodernists argues that values are specific to a given society at a given time, and that it's impossible to compare one set of values to another since to do so would require yet a third set of values. Since I would use my values to compare my values to your values, my values will always come out ahead. Any rigged contest like that would be immoral, thus all values systems must be equal on their own merits. (Postmodernists stock in trade is the Stolen Concept.)
The moral fundamentalists, on the other hand, believe that values come from some supernatural or extra-rational source. Whether relying on holy texts or what just "feels right," they argue that values come to us fully-formed and immutable. Some external agency, whether God or some deep part of the soul (never the rational mind), gives us values which are complete and correct, and anyone who disagrees is either not seeing clearly or is trying to excuse immoral desires. Despite deeply felt conviction, however, fundamentalist ethics are just as bankrupt as moral relativism and for the same reason. Values themselves can be subject to testing.
Medicine is a great example. Medical ethics is a complex and demanding field with a vast body of thought that stretches back to Hippocrates. While the edifice is worthy of study on its own, it is rooted in some core values. Doctors value life over death, comfort over pain, vigor over lassitude -- in short, all those attributes associated with well-being. Could we imagine a system of values that would reverse these preferences? Not really. That's not just a modern or Western bias -- the core value of heath is universal because it's derived from human nature. An alternate system of values will be about as successful as an animal born with a preference for seeking out and consuming deadly toxins. Here we have a clear-cut case of an "ought" -- medical ethics -- being derived from an "is" -- the facts of human biology.
There is an even more essential value than the health of our bodies; that is truth over falsehood. Getting things right matters. Even if values were independent of what exists, it would be critical to have the correct facts about the world so as to apply our values correctly. Without true inputs our judgments and actions are worthless at best, deadly destructive at worst. But since values themselves also built upon an accurate apprehension of nature, the world, and of each other, truth is essential not only for deciding right from wrong, but in determining what is right and what is wrong in the first place. Truth is the first moral value.