Page "Epistemology" Paragraph 14

In many of Plato's dialogues, such as the Meno, and in particular the Theaetetus, Socrates considers a number of theories as to what knowledge is, the last being that knowledge is true belief that has been " given an account of " — meaning explained or defined in some way.

According to the theory that knowledge is justified true belief, in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have a good reason for doing so.

One implication of this would be that no one would gain knowledge just by believing something that happened to be true.

For example, an ill person with no medical training, but with a generally optimistic attitude, might believe that he will recover from his illness quickly.

Nevertheless, even if this belief turned out to be true, the patient would not have known that he would get well since his belief lacked justification.