"If an action or policy has a suspected risk or harm, without scientific consensus that their will be no harm, then the burden of proof lies with those advocating an action or policy."In Europe, this principle is ingrained in the law. Many environmentalist are pushing hard to see it implemented in the United States. As a principle, it negates technological advancement until 100% certainty is obtained. That is simply impossible to achieve. The entire notion of scientific consensus is an abdication of rational thought in a field where rational thought is essential.
Philosopher and futurist Max More offers an alternative, Proactionary principle:
"People’s freedom to innovate technologically is highly valuable, even critical, to humanity. This implies several imperatives when restrictive measures are proposed: Assess risks and opportunities according to available science, not popular perception. Account for both the costs of the restrictions themselves, and those of opportunities foregone. Favor measures that are proportionate to the probability and magnitude of impacts, and that have a high expectation value. Protect people’s freedom to experiment, innovate, and progress."Although More's discussion is a bit rambling, I believe he is on to something significant. Its a principle that accepts and combines the virtues of rationality and productivity. It also sounds similar to an approach to the unknown that Peikoff discusses in one of his pod casts (I can't recall which one).
That being said - I am reluctant to tout the More horn. More has shown a marked deficiency in understanding Objectivism, accepting many of the falsehoods perpetrated by the Brandens and their ilk.