Read: Selections from Aristotle’s Topics, Nicomachean Ethics Bk.I
Since we didn’t finish the Theaetetus this week, let’s focus on one suggested definition from the remaining part: knowledge is true judgment with an account. Imagine the following example, embellished from the dialogue: you are stuck in jury duty, listening to an argument that the defendant Joseph stole a pineapple from a grocery store. The prosecution brings forwards several witnesses who attest that they saw a man dressed in a pineapple shirt and wearing an allergy mask (so they could not see his face) acting suspicious around the premises, lifting pineapples up and looking around as if to check if anyone was watching, just before the theft took place. They then bring up a police witness that attests that he caught Joseph 30 minutes after the incident, with the remnants of a pineapple and wearing a pineapple shirt. They bring the shirt Joseph was wearing into the courtroom, having been collected as evidence, and all the witnesses confirm this is the shirt they saw the suspicious man wearing. You listen to the evidence, judge that Joseph is guilty, and think that you know, “Joseph stole the pineapple.” Further, you think that you have a good account or reason for judging that Joseph is guilty, since you know many people saw a man in a pineapple shirt looking suspicious at the right time and Joseph was found in a pineapple shirt.
Unbeknownst to you, the man wearing the pineapple shirt that all the witnesses saw was just a pineapple connoisseur with terrible allergies, lets call him Jonathan, who was in the store to view a rare shipment of the pineapples and a bit embarrassed to be checking them out in such detail in public. It was his bad luck that Joseph caught him outside after stealing the pineapple from the grocery store, and Joseph, in his adrenaline-fueled state after the robbery, held Jonathan up and forced him to switch clothes with him so that the police (he thought) would not be able to track him.
You judged that “Joseph stole the pineapple,” and it was in fact true that Joseph stole the pineapple. On the one hand, you have a good account for why you believe that: all the witnesses, the policeman catching Joseph in the shirt, the confirmation of the shirt as the same shirt. On the other hand, it was only by pure luck that Joseph was wearing the pineapple shirt that all the witnesses saw. Would you say that you know, “Joseph stole the pineapple”?
If so, why do you think this counts as knowledge? If not, and you think it is a counterexample to Theaetetus’ suggested definition, what exactly is wrong with his account? Can you fix it?