http://whatisthematrix.warnerbros.com/rl_cmp/phi.html
A topic that is recently discussed in my Philosophy lectures/tutorials.
Moral skeptism:
Let A be we are in the Matrix
Let B be we have a pair of hands.
Hypothesis 1: I do not know not A (I dont know I'm not in the matrix)
Hypothesis 2: If I do not know not A, I do not know B. (If I dont know that I'm not in the matrix, I dont know that I have 2 hands)
Conclusion: I dont know that I have a pair of hands.
Think about it.