Sunday, April 09, 2006

Contingency in Natural Law Theory

Most natural laws - such as the laws of physics - are understood to be metaphysically contingent. The world could have been such that these laws were different. Is that also supposed to be the case for ethics, according to natural law theorists? Is it a merely contingent fact that humans have "natural rights"? Surely the normative facts are supervenient - you couldn't have a world non-normatively identical to our own, but with different moral or other normative properties. If there are any moral laws at all, then they are metaphysically necessary ones: more like the laws of logic than those of nature.

If they were contingent, how could we tell whether we had rights or not? After all, there would be a world empirically identical to our own where we would lack rights. How could we possible know that we're not in that world? We would have all the same experiences and evidence. There doesn't seem any real difference between the worlds at all (certainly not any noticable differences), but that in one world we magically possess "natural rights", and in the other we don't. What does this difference amount to? I guess it would ground different normative facts. Perhaps it is wrong to kill people in one world but not the other. But that's ridiculous. A difference in moral properties must reflect a real difference in the world, and not in some free-floating moral "laws".

Anyway, I don't know anything about the natural law tradition, so let me ask my more informed readers: do natural law theorists tend to share these concerns, and so hold their moral laws to be metaphysically and not merely naturally (nomologically) necessary? (And if so, doesn't that make "natural law" something of a misnomer?)



  1. Surely the normative facts are supervenient - you couldn't have a world non-normatively identical to our own, but with different moral or other normative properties. If there are any moral laws at all, then they are metaphysically necessary ones: more like the laws of logic than those of nature.

    Richard, I think you need to make some more careful distinctions here. For example, something's being metaphysically contingent does not mean that the world could be just as it is with that thing failing to hold or not existing, at least not as you've used the term. The laws of physics, after all, meet the description above as well: they may be metaphysically contingent, but if they were different we would be living (if at all) in a strikingly different world. I think it's pretty clear that we couldn't have a world identical to our own with the exception of a different set of physical laws - or at least as long as we're willing to use the word 'identical' as having any sense whatsoever. But if this is the case for physical laws and, plausibly, moral facts, then they might well have very similar status. I don't think the sense in which 'the world could have been different' when it comes to, say, the natural law is in any way threatening to the natural lawyer any more than it is threatening to the physicist - it's just that if the world were terribly different then there would probably be a different natural law.

  2. It depends on what, precisely, you have in mind. It's fairly standard to distinguish between first principles and secondary principles. First principles are typically seen as strictly necessary (these are things like 'Good is to be done' and 'Evil is to be avoided' and other obvious cases). Likewise, anything that follows directly from these first principles is necessary. These establish (as it were) the framework for all practical conclusions about morality. They are indeed usually considered to be analogous to laws of logic; they are to practical reason what the the principle of noncontradiction, etc., are to speculative reason.

    There are other principles of natural law, however, that depend at least in part on contingent facts. The standard sort of example in the tradition has to do with private property: natural law theorists have generally held that by first principles everything in the world is for common use to mutual good; no moral conclusions about private property follow strictly from first principles (private property has a strong prudential basis, but this basis depends a great deal on contingent features of the world).

    On the misnomer question, I think you may be engaging in a bit of an anachronism. 'Natural law' in ethics is older, or at least has been entrenched longer, than the common use of 'natural law' to apply to the physical world. The latter was often seen as merely a metaphorical extension of the former. Aquinas suggests something like this, for instance: he holds that while ethical natural law is law in the strict sense (promulgated authoritative dictate of reason), physical natural 'law' is merely a figure of speech. So it's the use of 'law' for physical law that's a bit of a misnomer.

  3. Heh, fair enough, thanks for the explanation. I take it even the secondary principles are meant to supervene in the weak sense, i.e. you couldn't have a world non-morally identical to ours where private property is a bad thing (assuming it is a good thing here). Given the contingent psycho/sociological facts, the moral facts follow. In this sense we could see all moral principles as necessary conditional truths: necessarily, if conditions C hold, then the moral conclusion M does too. There's no possible world where C is true but M false.

    Contra Dr. P., that seems different from physical laws. At least, I suggest in my recent post Are Laws Internal to Worlds? that there could be spatiotemporally identical worlds with different physical laws governing some unactualized events (and thus yielding different counterfactual properties).

  4. I think you're right about weak supervenience and conditional necessity. One of the important features of traditional natural law theory that sometimes drops out of later versions is the recognition that the conditions can become extremely complicated very quickly, and therefore that it sometimes takes considerable skill -- almost a highly-practiced art -- to determine the right secondary principles, particularly since (in some cases) a very slight change in conditions might require a very great difference in principle. But given the right conditions, all the secondary principles are necessary.


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