II – Naturalistic Theories An ethical theory is naturalistic if and only if it attempts to define a clearly evaluative term like “right action” in terms that only involve natural facts.
A. The Theory of Natural Law In the second half of Chapter 4 you encountered the Theory of Natural Law, which is the most widespread naturalistic theory. It consists of two parts:
It follows from natural facts that some features in nature have a purpose. (The lens in the eye is for focusing light, our sexual organs are for reproduction, plants are for recycling CO2, predators are for controlling the population of herbivores, etc.)
Right action = an action consistent with the natural purposes;
Wrong action = an action contrary to the natural purposes. Unnatural behavior is wrong.
This theory has two major defects: One is that it is quite difficult to work out from natural facts alone what purpose things have. Is there a fact of the matter about the purpose of a cow? Is it to make shoes, glue and hamburgers? That is not at all obvious. Furthermore, how do we distinguish the unnatural from the merely unusual? For example, there are equally many homosexuals as there are left-handed people, but proponents of Natural Law Theory don’t typically consider left-handedness to be “unnatural,” and it’s hard to see why they do think this of homosexuality.
I want to focus on the second and more interesting defect, however: Suppose that we could work out some factual criteria which would distinguish what is natural from what is unnatural. It still seems fair to ask: What’s so good about the natural, and what’s wrong with the unnatural? Not enough people ask this question. At least since Socrates, philosophers should have known that not all natural things are good.1 Even now, we prefer products with natural ingredients when we know very well that natural things can kill us. There is nothing more natural than viruses, parasites, cancers and death. However, I applaud every effort we take to prevent these things from following their natural course. I want to fight them all, and feel no inclination to just accept what is natural. If a scientists creates some very unnatural concoction that destroys cancer without hurting healthy cells, that will be a very good thing.
Many on the political right say dumb things like “It’s unnatural for women to choose work over motherhood,” and many on the political left say dumb things like “It’s unnatural to live in concrete cities, eat engineered foods and depend on technology that we cannot comprehend.” Both mean that these things are bad because they are unnatural. They usually draw people into a debate whether or not these things really are unnatural, but that’s beside the point. Let’s say that they are. The real question should be: So what if they’re unnatural? Are these things good? If we judge that it is bad to eat engineered foods, it should be because it’s somehow dangerous, or less nutritious, or needlessly expensive. If they are none of these things, who cares if they’re unnatural? Many unnatural things are good!
In the debate about global warming, much attention is focused on the question about whether the warming (which is clearly happening) is a natural phenomenon, or whether it’s caused by human activity. This is a notoriously difficult question to research, because there occasionally are periods of natural warming and cooling. Most people feel that if the present warming is another of these natural fluctuations, then we have no responsibility to counteract it. To me this sounds like another instance of this mistaken view “If it’s natural then it must be OK.” I strongly doubt that the present warming is natural, but even if it were, would that make it less bad? A natural warming, just like a man-made warming, would melt polar ice and leave many of the world’s cities under water. It would shift weather patterns and cause massive famine, species extinctions, deadly storms and many other bad things. So suppose we could stop and reverse global warming. Should it really matter whether or not the warming is natural? Isn’t it bad, and worth stopping if we can, even if it is natural?