You have no business to be an unbeliever. You ought to stand for all the things these stupid people call superstitions. Come now, don't you think there's a lot in those old wives' tales about luck and charms and so on, silver bullets included? What do you say about them as a Catholic?'
'I say I'm an agnostic,' replied Father Brown, smiling.
'Nonsense,' said Aylmer impatiently. 'It's your business to believe things.'
'Well, I do believe some things, of course,' conceded Father Brown; 'and therefore, of course, I don't believe other things.'.

The Dagger with Wings (1926)