I would characterize the 'hopeful' statement as one of blind faith -unproven assumptive posit...
I'm not entirely certain I understand the point you're making here, but I'll guess that you're saying that Weinberg's view that the human mind is not beyond the hope of scientific understanding is somehow based on 'blind faith'. Well, you might be right if the last 400 years or so of scientific discovery hadn't happened. But they have, and we're the heirs to a still-unfolding understanding of the phenomena of nature that is truly cosmic in scope. Given that history, Weinberg's doesn't seem to be 'blind faith' at all, but rather a reasonable take on what future investigation might show.
'Blind faith' seems to me to be something along the lines of what motivates suicide bombers to blow up themselves and others.
-just more hope and faith... -backward looking with eyes open to history does not contravene fact that forward looking into the future is blind... --unless Weinberg a clairvoyant he simply makes unprovable predictions that he touts as proofs for whatever he posits... -he builds a house of cards...