Science can never establish criteria for moral behavior, because it is unable to make distinctions between facts and values.
Some thinkers, such as Sam Harris, have tried to claim that science can provide us with the criteria for moral decision-making. In a nutshell, the claim is that empirical observation can determine what is best for human flourishing.
By observing the effects and consequences of our behavior on others and on ourselves, we can, so theory goes, determine which activities are best for us. Neuroscience, for example, can determine which activities bring about positive brain chemistry in us; sociologists and psychologists can determine which activities lead to social harmony; statisticians can point out which activities result in the best outcomes over a period of time.
There are a number of significant problems with this theory. I’ll just focus on one here: namely, Harris’ claim that fact and value are the same thing. Note that the theory that there is no fact-value distinction is necessary for the “science as ethics” argument.
First of all, the claim that facts are equal to values relies on circular reasoning. To determine what is “best” for humans already assumes that there is a standard of good, better and best. To say, for example, that not using corporal punishment is better than using it, relies on a notion of what is good. Appealing to the physical harm done to a child as being evidence of unwanted abuse is not a scientific conclusion, but a moral one. “Bruising a child with a wooden paddle is bad” is not a conclusion of science: science, if it is to be of any help to ethics, requires this value-input in order to draw a conclusion about the value of corporal punishment. Even more basically, to say that life is better than death already contains within it a moral assumption about the value of human life. Nietzsche already noted, back in the 19th century, that those who claim they do not need Christian morality (he was writing for post-Christian Europeans) to be good, were already tacitly relying on Judeo-Christian notions of good and evil in the effort to establish independent moral criteria.
Secondly, the assumption that science can determine what best constitutes human flourishing is simply another way of arguing for teleological ethics. Teleological ethics is a moral code based on judgements about good outcomes. But teleological ethics has the added burden of distinguishing between means and ends. Some, for example, argue that the dropping of the atomic bomb on Hiroshima was justified because it brought a more-timely end to World War II. What would science have to say about that? Well, we’re back to the value-fact distinction: the dropping of the atomic bomb resulted in the deaths of many tens of thousands of people. But it potentially saved, so the argument goes, the lives of one million US troops. Harris’ scientific theory does not account for the distinction between means and ends. Ostensibly, the death of a hundred thousand Japanese civilians was a bad thing (as if we need science to tell us that). But does that bad thing outweigh the potential deaths of American troops? How is this “weighting” of means and ends to take place? Given that we are unable to go back in time and weigh up both outcomes, what scientific test would Harris propose to measure potential verses actual outcomes?
Thirdly, Harris’ science-based morality is inadequate because it is too broad as it conflates facts and values. As Aristotle noted, a definition needs to be such that it encompasses everything within a category, leaving nothing out, and not adding anything outside that category. For example, the word “transportation” cannot be so broad so as to include pineapples and picnic baskets. “Something that is nice”, while descriptive of a holiday, is too broad to be a definition of a holiday because it could also include chocolate ice-cream.
A “value” is something we consider to be important and worthy of pursuit or possession. A “fact” on the other hand, is some discrete piece of information which describes some facet of the world. “Canberra is the capital of Australia” is a fact, but it is not a value. “I think I will have ice-cream tomorrow” indicates a value I place on ice-cream, but it does not establish any fact. It may be a fact that I am thinking that I want ice-cream tomorrow; but there is no fact constituted in a real circumstance. I may change my mind. Tomorrow, I may go off chocolate ice-cream and prefer mint instead. Values are not limited to the present, whereas facts are. It is not a fact that tomorrow or the day after I will have ice-cream: that will only become a fact when it happens. But it is a value for me today. People pursue things, not as facts, but as values.
Finally, and perhaps most significantly, Harris’ use of the term “flourishing” and “well-being” represents a radical departure from the Greek notion of “flourishing” (eudaimonia) that has formed the basis of much of Western thought. “Well-being’ is not synonymous with positive brain chemistry, or with economic well-being, or with physical health. If that were the case, then anyone who was poor, or suffering, or struggling, could not be said to be either moral or virtuous. In fact, we humans often sacrifice physical well-being for things we value more. Someone, such as a Maximillian Kolbe, may sacrifice his life for his fellow human being. Kolbe died a terrible death as a result in an Auschwitz starvation bunker. Anyone examining his brain chemistry would have had to conclude that he was the most miserable of human beings. Perhaps scientists would have counseled him not to sacrifice his life since it did not constitute his “well-being”. He did, nonetheless, and brought a shining beacon of humanity into an otherwise-hellish place. Western civilization is built on such notions of altruism. Perhaps in Harris’ scheme, there is no place for such altruism: but I doubt there would be a scientific test available to say whose value is better.