That's right, and it's not easy but what's the alternative? You can throw up your hands and not even try to get it right. That's what is advocated by Socrates and the radical skeptics who say it's never possible to be confident of anything. And what do you do then? - You give up studying nature and you retreat to wishful thinking about "virtue" - and let others make decisions for you.
That's a high price to pay to just to win a pat on the back from modern philosophers.