The Cow in the Field
Farmer Field is concerned about his prize cow, Daisy. In fact, he is so concerned that when his dairyman tells him that Daisy is in the field happily grazing, he says he needs to know for certain. He doesn't want just to have a 99 per cent idea that Daisy is safe, he wants to be able to say that he knows Daisy is okay.
Farmer Field goes out to the field and standing by the gate sees in the distance, behind some trees, a white and black shape that he recognises as his favourite cow. He goes back to the dairy and tells his friend that he knows Daisy is in the field.
At this point, does Farmer Field really know it?
The dairyman says he will check too, and goes to the field. There he finds Daisy, having a nap in a hollow, behind a bush, well out of sight of the gate. He also spots a large piece of black and white paper that has got caught in a tree.
Daisy is in the field, as Farmer Field thought. But was he right to say that he knew she was?
--from Cohen, M. 1999. 101 Philosophy Problems. London: Routledge.