What is knowledge? : Internal justification

Philosophers say that in order for one to KNOW a proposition, three conditions have to be met: a) the proposition is true, b) one believes the proposition, and c) you are justified in believing the proposition. This analysis of knowledge is referred to as the JTB account: knowledge as justified true belief. What interests me most is that philosophers disagree in ALL three conditions. The last condition seems to be the philosophers' s favorite topic. I device two example to show the disagreement between philosophers known as internalists and those known as externalists.

First, suppose John has a dog. Every evening when John comes home, he opens the door and finds the little dog already sitting besides him. The dog smells the usual odor of John before the door is open. Intuitively, we will not refuse to admit that the dog knows John is back. In this case, we attribute knowledge to animals.

Next is a scene depicted in the movie, Minority Report. Imagine a girl who is constantly haunted by terrible dreams about murder at night. What she sees in her dream is real murder in near future, although she does not recognize her psychic ability at that time. Later a scientist proves that those murders really happen after the girl dreamed about them. And according to predictions of the girl and two other boys who also have the psychic ability, the police build a system called precrime to prevent possible murder, which the movie is all about. Do you think she kNOWS the murder before the scientist proves her psychic ability?

Here we meet a controversy. The dog does not have the idea that its senses are reliable. Neither does the girl had the idea whether her sense, the psychic ability, is reliable. But we attribute knowledge to the dog, but not to the girl. Why? Is it because the psychic ability is something not as common as ordinary senses like taste, smell, or sight? If so, let us view the case just as a thought experiment. So it suggest that in order to know, one should recognize the reliability of the senses. On the other hand, the example of the dog suggests that such a recognizability is not necessary for knowledge. Senses is one common source of our knowledge; the recognizability of their reliability is one example of the direct recognizability of justification -- what the internal justification is.

So the fundamental question is whether the internal justification is necessary for knowledge?