“I admire especially a certain prophetess who lived beside a lake in northern New York State about the year 1820. She announced to her numerous followers that she possessed the power of walking on water, and that she proposed to do so at 11 o’clock on a certain morning. At the stated time, the faithful assembled in their thousands beside the lake. She spoke to them saying: ‘Are you all entirely persuaded that I can walk on water?’
With one voice they replied: ‘Yes, we are.’
‘In that case’, she announced, ‘there is no need for me to do so.’
… And they all went home much edified.”
— Bertrand Russell, Unpopular Essays (1950)
Odeboyz's Blog 
Pretty sure, I’ve seen similar arguments used without irony.
Thank you for your comment
Russell wasn’t just a brilliant mathematician and philosopher he also had a wry humour. That’s why there is so much in his works that are very quotable.
so true…. and folk believed the winning lie of £ 350 000 000 a day for NHS if they voted Brexit