The sceptic will say, 'It may well be true that this system of equations is reasonable from a logical standpoint, but this does not prove that it corresponds to nature.' You are right, dear sceptic. Experience alone can decide on truth.
There is a difference between responsible criticism that aims for success and defeatism that refuses to acknowledge anything but failure. Hindsight alone is not wisdom, and second-guessing is not a strategy.
O why do I ever let anyone read what I write! Every time I have to go through a breakfast with a letter of criticism I swear I will write for my own praise or blame in future. It is a misery.
It's useful for activists just to be out there to keep you mindful and not get complacent, even if ultimately you think some of their criticism is misguided.
There is a difference between responsible criticism that aims for success and defeatism that refuses to acknowledge anything but failure. Hindsight alone is not wisdom, and second-guessing is not a strategy.
Either criticism is no good at all (a very defensible position) or else criticism means saying about an author the very things that would have made him jump out of his boots.