“What alchemy there was in human beings.”

“Elephants can remember, but we are human beings and mercifully human beings can forget.”

“I think human beings matter more than stones. (Signor Richetti)”

“In conversation, points arise! If a human being converses much, it is impossible for him to avoid the truth!”

“I know there's a proverb which that says 'To err is human,' but a human error is nothing to what a computer can do if it tries.”

“But I know human nature, my friend, and I tell you that, suddenly confronted with the possibility of being tried for murder, the most innocent person will lose his head and do the most absurd things.”

“It's really very unpleasant. And not being able to say anything to answer back makes it rankle more, if you know what I mean.”