Read another response by Nicholas D. Smith
Read another response about Knowledge
Knowledge is usually said to be justified true belief (with some caveats). However, it seems that a great deal of what we "know" is actually knowledge we have received from third parties - our parents, our teachers, authors of books and websites, friends, and so on. If we define justification so broadly that it encompasses things we learn from third parties, what is to stop us from assuming that anything we learn from anyone else (or any specially qualified individual) is knowledge? Does this mean, according to the justified true belief understanding of knowledge, that most of what we think we know is not actually knowledge?