sagan makes a good point but he errs in so many ways that he can’t be assumed to be speaking philosophically, and so i don’t know how to respond. apart from this bogus strawman he constructs (himself) and proceeds to vigorously burn down successfully (because after all he’s the manufacturer) he seems to be in a hurry to dismiss whatever knowledge cannot be arrived at scientifically (and even worse with tools available during his time). the problem with ‘knowledge’ is well-known and unsolved.