I like the example of seeing a clock as you walk past. It says it's 2:30. You believe that the time is 2:30. That seems like a perfectly reasonable level of jus

I like the example of seeing a clock as you walk past. It says it's 2:30. You believe that the time is 2:30. That seems like a perfectly reasonable level of justification -- you looked at a clock and read the time. If unbeknownst to you, that clock is broken and stuck at 2:30, but you also just happened to walk by and read it at 2:30, then do you "know" that it's 2:30? I think a case can't so much "disprove" JTB, so much as illustrate that adopting a definition of knowledge is more complex than you might naively believe.