Lots of philosophizing here about the precautionary principle.
While the precautionary principle is certainly a mainstay of a rational world view, I don’t know if I’d call it a scientific postulate, as opposed to an empirically derived theorem: Those who tout these kinds of technologies have always lied about every aspect of them, and have always proven to have none but evil motives, whatever altruism they pretended to. Therefore, no rational person who’s not a criminal himself would hold anything less than the position that the burden of proof is on the aggressor: To prove that the product is necessary, that it’s safe, that it increases the general prosperity for all of humanity, and that his motives are truly on the up-and-up.
Indeed, we can’t argue with those who are so convinced by the unanimity of the malign pattern that they’re satisfied to reject all current and future such products out of hand. This, too, is rational, given the overwhelming evidence.
Elsewhere I’ve seen reference to “the [unnamed] fallacy of giving a proven liar the benefit of the doubt”. While for obvious reasons this fallacy isn’t as well-named and publicized as spurious applications of the “ad hom fallacy”, it’s at least as important in constructing a rational world view and deriving guidelines for action from it, since the world is full of proven liars, for example anyone who touts unproven* technologies like GMOs.
To me it seems that’s the real, or at least primary, nature of the precautionary principle, and the core rationality of it. Like the rest of our real science, it’s empirical, based on our demand for an understanding of reality, rather than an illusion conjured to assist a venal or ideological imperative, and imposed from the supply side of the mind, which is seldom rational or good, but always aggressive.
These are just a few opening remarks. I’ll have lots more development of these ideas.
*Of course by now we’ve amassed enough evidence that we’re either over or at the threshhold of a reasonable doubt, that GMOs are in fact unnecessary, don’t work, are unsafe, and have none but destructive socioeconomic and political effects.
Again, one can easily argue we’re beyond a shadow of a doubt.