Precautionary Proverb

Via Juan Non-Volokh, I've found something I keep meaning to search for -- a contrarian environmentalism blog, The Commons (hopefully it proves worth reading consistently, though I'm probably jinxing it here). In the posts linked to by Non-Volokh, two authors take Jeremy Rifkin to task for an article promoting the precautionary principle (PP). Despite Rifkin's assertion that the PP is a groundbreaking post-Enlightenment new idea, it's basically classical conservatism -- "the world is extremely complex, so don't change anything unless you're really really sure you know what you're doing." The PP merely emphasizes the environmental applications, whereas conservatism focused on social changes.

Joel Schwartz argues that Rifkin is inconsistent in his use of the PP, since he's decidedly un-precautionary about changes he likes (such as hydrogen fuel). But I think the problem is in a slightly different place. Rifkin mistakenly characterizes the PP as a decision rule. In reality, I think the PP is a proverb. It's used to evoke a certain attitude and declare your feeling that it is applicable to a certain situation.

Schwartz rightly points out that total precaution is unfeasible. But so is total risk-seeking. We have to find some balance where we are willing to take the plunge despite a degree of uncertainty. What the PP amounts to is an assertion that, in the opinion of the person invoking it, we haven't been cautious enough. One could also invoke the inverse proverb -- "nothing ventured, nothing gained" -- if one believed we had been too cautious. Neither of these proverbs constitute a reason for a particular non-extreme level of risk or a rule by which we can test the appropriateness of our chosen level of risk. Rather, they are expressive claims that call on decisionmakers to consider whether they've shown too much/little caution. It's easy to get caught up in the beneficial possibilities of a course of action, so the PP can act as a reality check (and conversely for invoking "nothing ventured" to a worrywart).

Thus, the inconsistency of Rifkin's application is not a sin, by this understanding of the PP -- or at least, it's no more or less of a sin than favoring hydrogen fuel but opposing GM crops. One can dispute his implicit risk assessments in each case, but the PP is no more than an expression of the relationship between his preference and the course of action actually being pursued.