Is truth necessary for knowledge? The JTB, or Justified True Belief, definition of knowledge is a popular one. I know some have argued 'Justification' is not necessary for knowledge and others that 'Belief' is not a part of knowledge. But, no one has claimed that truth is unnecessary for knowledge.

In the past, people have claimed to have knowledge on certain subjects (for example: information about our planet/solar system) which have been proven otherwise. So, is truth a necessity of knowledge?