(1) 'Man is a social animal because he is gregarious.'
(2) Jones (at the bank): 'I would like a loan.'
Banker: 'What recommendations or references do you have, something to
establish that if we loan you the money, you will pay it back?'
Jones: 'Well, I can refer you to my friend Quimby; he'll vouch for
me. He'll tell you that when I say I'll pay, I will.'
Banker: 'But we don't know Quimby, so how do we know he can be
trusted?'
Jones: 'Oh, I can assure you that Quimby can be trusted.