The debate of rationalism and empiricism regarding how we acquire knowledge stands on the foothold that knowledge exists. But what is knowledge? In classic Green, philosophy knowledge is a justifiably true belief where three conditions must be met: You should believe it is true, you have evidence to justify your belief, and you are correct. If any two of those conditions are not met, then knowledge does not exist.
Gettier’s famous thought experiment challenged these conditions. Suppose a farmer is concerned about his cow being stolen. He asks a friend whether he has seen the cow. His friend assured him that he has seen his cow in the fields. The farmer checks and discovers a black and white shape of his cow, yet the cow was hidden among the trees what he finds in the field is black and white paper, and realizes that his friend must have mistaken the paper for his cow. Here, the farmer believed that the cow was in the field, it was factually true and justified by the testimony of his friend – but did he truly have knowledge of what it is in the field?
