I think Maria V's point is a good one. Darcy is making his opinion strictly on what he wants to see. He only observed her one evening, he never took the time to talk to Jane, much less get to know her, but he decided that she is a soft pliable young woman who could be persuaded by her mercenary mother. He did not take the time to find out, he just presumed judgment on someone he didn't even know, or care to know. I wish Elizabeth would think more fully on that, because Darcy should be called on his arrogant argument. I agree somebody should show him his arguments had more holes than Swiss cheese. But, I have always been a proponent that Bingley was never truly held accountable for his conduct in the whole situation. He should have known better, and should have been man enough to make his own observations and decisions, and should be held accountable as such. If he decided to trust Darcy, then he should pay the consequences.