Tiffany looks around at an old-fashioned clock sitting on the sideboard which shows that the time is 6.56.
"Yeah, it is four minutes to 7," says Tiffany.
Following Tiffany's glance, Claire says, "Oh, that clock doesn't work. It always shows 6.56. So you are mistaken."
Tiffany looks at her mobile phone and says "Really? I think you are mistaken as my phone confirms that it is 6.56 at the moment."
(Adapted from Bertrand Russell, Human Knowledge: Its scope and limits, 1948)
Does Tiffany have a legitimate claim to "knowing" the time after viewing the stopped clock?
If the time was 6.56, and Tiffany believed it was, and justified that belief by reading the clock, does she have knowledge?
The notion that knowledge is 'justified, true belief' suggests that she does. Perhaps we ought to change the definition of knowledge? How would you change the definition?