ORDINARY
There are regular things, which we all pretty much understand completely. 2 + 2 = 4.

SPECIALIZED
There are complicated things, which a small % of the population truly understand, but we all believe: DNA fingerprints/sequencing is admissible for evidence

COMPLEX
Then there are things that are so complex that even the most elite folks in the field have lots of specific knowledge, but the complexities of the systems elude complete closed-form-solutions: How does the brain work? How does the climate work, and what if any changes might have ill effects? How does the economy work and what changes create jobs??

COMPLEX stuff is what we're talking about here, and as a result if your standard for decision making is perfect knowledge, then you never take any action on a brain tumor, or to fix the economy, or to fix the climate. Because NOTHING in this space is -- likely in our lifetime -- to be known in the closed-form way you hope.

If your standard is that "the jury is still out" and that it's a "supreme display of hubris" to take action based on the recommendations from the overwhelming majority of the best educated people on the subject???? Then I sure hope you never get a brain tumor, because you'll never decide to take any action about it -- because the science (and treatments) are unsettled.

Next time we have an economic upturn or downturn, I hope you don't post that you know why it happened, or what we should do to promote jobs growth, because the jury is out on that, you supremely hubristic blowhards.

In these situations, I choose to listen to the best doctors, scientists, and economists, and contribute my energy to the solutions that I think are viable... Be it surgery, pollution control, or tax policy.