Thursday, December 01, 2005

“Homosexuality is immoral because it is unnatural” (non sequitur)

An unnecessary but common response to this claim is to dispute that homosexuality is unnatural by pointing to the abundant evidence of homosexuality in non-human species. But even if homosexuality were unnatural, this wouldn't make it wrong or unhealthy. If we were to shun everything that is unnatural, we'd be forced to abandon our houses, clothes, medicines, technology, art and much else. Clearly there are some unnatural things we consider good. Likewise, we take earthquakes, tsunamis, snake bites and sunburn to be natural, but not good. And those items on the supermarket shelf proclaiming all natural ingredients like salt, sugar and fat are not good for your health. Whether or not homosexuality is natural or unnatural tells us nothing about whether it is right or wrong, desirable or undesirable. The argument is a non-starter (and for those interested, an example of an argumentative fallacy called the appeal to nature).

Suppose for a moment that for some reason all the other unnatural things that we like are permissible because they have nothing to do with sex, that sex is a special case in which virtuousness always coincides with naturalness (we'd be guilty of a different argumentative fallacy called special pleading, but let's allow it in this case). If this were so, then we might look to the sexual behaviour of other species for examples of how to behave. We could model our behaviour on bonobo chimpanzees, who continually use sex to reinforce social bonds within a group (same sex or not)[source], female praying mantises who eat their mates once they have served their function, ducks who engage in homosexual necrophilia [source], dogs who mount their owners' legs, and so on. Homosexuality and a whole lot of other things would be permitted under this kind of moral philosophy. Not only that, but our guidance would be riddled with contradictions arising from the fact that different species have different sexual practices. For some species, promiscuity is the norm. For others, monogamy is, and so on. We would have to ask what is natural for humans specifically, but if we are contrasting 'natural' with 'man-made', what sense could there be to such a question?

Even if we wish to cling to the view that 'natural' equals 'good' and even if we can ignore the fact that nature seems to make contradictory judgements about what is good and bad, it would still be difficult to argue that homosexuality in humans is any more natural than practices like celibacy, something that few are inclined to condemn. If homosexuality is wrong or unhealthy, this kind of argument simply does not show it.

Note that the claim that homosexuality is immoral because it is unnatural is a part of a more general family of arguments, which also includes justifying promiscuity by arguing that monogamy is unnatural, or eating meat by arguing that vegetarianism is unnatural. As with homosexuality, nature has no consistent attitude towards these things, and even if it did, no moral conclusions could be drawn about these practices (at least on this basis) since 'natural' simply cannot be equated with 'good'.


  1. While I agree with your conclusions I think this arguement is hampered somewhat by the problem of defining what natural is. There are two slightly different definitions I can think of:

    1. Something that is not man-made or as a result of mans actions on the world, which would include natural disasters, salt, sugar and fat as you suggest in the blog.

    2. Some component, process or constraint that has been consistant enough in our evironment that it has effected our evolution. In this case a diet rich in sugar, salt and fat is not natural because it represents a shift from the conditions our physiology evolved under. The same arguement could be made for natural disasters (perhaps tentatively). Under this definition, natural still wouldn't mean 'good' but perhaps 'safer'. Perhaps you disagree with this interpretation, just an idea.

    However, non of this alters the conclusions that you have come to regarding homosexuality.

    Very nice blog by the way.

  2. Thanks, you raise some interesting points. The word ‘natural’ is certainly used with different meanings in different contexts. My argument is valid for the first definition you list, which I take to be the relevant one, but if people who make this kind of argument against homosexuality aren’t using a definition along these lines, then I’ve just knocked down a straw man. To escape my objection, proponents of the opposing view would be forced into one of two positions - they would either have to argue that things like our houses, clothes, technology, art, and cultural traditions are on some objective grounds actually undesirable after all, or that these things are not ‘unnatural’ under the definition they are using. Note that the argument is about unnatural things rather than natural things. It may be that natural things are sometimes good and sometimes bad – it doesn’t matter for their argument so long as unnatural things are always bad. This means it would be beside the point to argue that the various undesirable things that I claimed were natural are in fact unnatural.
    Although my argument doesn’t rely on there being natural things that are undesirable, this possibility has interesting implications so it is worth a digression. You are right to point out that, although ingredients like sugar, salt and fat are not themselves man-made, it is the man-made technology that we use to farm and refine them that makes it possible to consume these ingredients in unhealthy quantities. Salt, for instance, is bad for us in large quantities, but we actually need small amounts of it in our diet. Our value judgements should really be about the amount of salt we consume rather than salt per se, and in a context where we are more concerned with taste than nutritional value, we would have a different idea about what that optimal amount is. This highlights a distinction that I’ve glossed over between judging something to be ‘good for’ some specific purpose versus just plain ‘good’. I leave it to the reader to consider what it could mean for something to be ‘good’ without reference to what it is ‘good for’. There are many conceivable things that salt is good for and many that it is downright bad for. It being natural doesn’t have much to do with it. The case that natural things are not always good is made more dramatically by natural disasters because they clearly have a lot of negative consequences. They might have fortuitous consequences occasionally (a hurricane could save you money if you were already planning to demolish one of the buildings in its path), but they usually have many more negative consequences.
    Note that there is a history of thought that has an enormous stake in showing that nature is good. Eighteenth century optimists like Leibniz tried very hard to reconcile the reality of a world in which tragedies are commonplace with a belief in a perfect and all-loving deity.
    The existence of undesirable things in nature has interesting religious implications, but also more mundane ones. When you’re told that some product on the supermarket shelf contains only natural ingredients, advertisers want you to believe that it is good for you, but this isn’t necessarily true. We’re always being told to buy natural artery-clogging butter in preference to margarine, or breakfast cereals that contain “no artificial flavours or additives” but that are nevertheless full of sugar and other natural ingredients in unnatural amounts, and so on.
    The belief that nature is essentially good also underlies therapeutic approaches like naturopathy, but to adopt this view would leave us uncritical of natural products like bee pollen and royal jelly, which are widely sold in health food shops under this premise despite the evidence that suggests we should have serious concerns about their safety (
    The issue is not so much about the natural/unnatural dichotomy, but whether the long-term effects of something have been adequately tested or not. Our ancestors have had plenty of time to categorise the products of nature into good and bad, to distinguish medicines from poisons and so forth. Hence, if something hasn’t been adequately tested, it is usually because it is a newly manufactured product, but it can also be because it is a novel application of something that is naturally occurring. If something is unnatural or unprecedented, it is justifiable that we treat it with caution. But as I said earlier, even if all unnatural things are bad, this wouldn’t mean all natural things are good. Your ears should prick up whenever you hear justifications along the lines that such-and-such a product can’t be that bad for you because it is natural, that it is only natural that you react in such-and-such a way, that it is natural that everyone has at least some prejudices, and so on.
    Anyway, thanks for your insightful comment – it’s hard to believe you were drunk while you wrote it.