Greyfan --
Thanks for your interesting points. Before I address them, I'd like to insert a little disclaimer: The view I'm about to defend is a view towards which my thinking has been trending recently. It is not a view I have held for most of my life, and I am not even sure I hold it now -- maybe I'll get there maybe not. So if I defend them now, it is in a spirit of exploration, not ideology.
Greyfan wrote:Formulations of the laws of nature can be tested against an observable reality, with the results confirmed or rejected elsewhere, based on their validity.
[...]
Formulations of common law cannot be tested, except within the subjective perceptions from which they arose in the first place,
I would dispute that. For an interesting recent example, consider the hacker community (in
the noble sense of the word -- the community that built the internet, the Linux operating system, etc.). Eric Raymond, a hacker and amateur sociologist, discovered a few years ago that hackers act as if they respect an elaborate set of property rights in ideas and problems. These rights have never been explicitly negotiated, but they nevertheless turn out to be very similar to Lockean rights in newly settled land -- the kind of rights America adopted in the homestead act. If you're interested in details, you might be interested in Raymond's article,
Homesteading the Noosphere.
It would appear that discoveries like this do open the possibility of objective tests. You watch out for conflicts that have happened among settlers in the Wild West, but not yet in the hacker community. Based on what you know about homesteading law, you predict which party to the conflict will make which ethical, (philosophical, moral ...) argument, and how the conflict will eventually be resolved. Then you wait for the conflict to happen, and when it does, you compare the outcome to your prediction. Because hackers don't study law, there is no reason to believe the outcome will be analogous to the outcome in settlement conflicts. Except if there is something objective about the situation that determines the outcome.
Wouldn't this be the kind of test you say doesn't exist?
Greyfan wrote:and would have no application, for example, in an alien culture, although an alien culture could test our scientific theories. When the only basis for our consideration is custom and popular opinion, however, there is no correct answer for which to strive.
As someone who occasionally attends scientific conferences, I have visited several fairly alien cultures. While there are indeed some customs that are different, the bulk of them are similar to ours. But similarities are boring and differences are interesting, so nobody pays attention to the similarities. Nevertheless, you can predict pretty well, based on your native customs, whether a particular act will evoke moral emotions such as outrage, shame and pride in your alien hosts. At least this has been my experience.
Greyfan wrote:I believe the laws of physics can be discovered but not created. I believe the laws of ethics can be created, but not discovered.
That's not how I see it, at least not in the context of this discussion. I am willing to start with the assumption that laws of physics and laws of ethics are both social constructs. But as a matter of observation, most social constructs turn out to be neither valid laws of physics nor valid laws of ethics. Most of these constructs collapse shortly after construction, a few don't -- and these few have a number of predictable features in common.
This is a fact worth paying attention to, and it is a fact that merits an explanation. My explanation is that in both ethics and physics, there's a reality out there which constrains which social constructs can survive. I admit the constraints are more loose in the case of ethics, but that doesn't change my fundamental point.