PHILOSOPHY STUDENT: “I just had lunch an hour ago.”

PHILOSOPHY PROFESSOR: “You mean you ‘think’ you just had lunch.”

PHILOSOPHY STUDENT: “No, I’m sure.  I ate six stuffed peppers.”

PHILOSOPHY PROFESSOR: “That’s still no proof.  You could think you ate six stuffed peppers.  It could all be in your mind.”

PHILOSOPHY STUDENT: “That’s impossible, Professor.  I know I had lunch because I have indigestion, and it’s in my stomach not my mind.”