ABSTRACT
This chapter introduces a definition of knowledge as warranted true belief and argues that misinformation presents a three-pronged threat to knowledge, so construed. Misinformation poses a deceptive threat insofar as it tends to cause false beliefs, instead of true ones. Misinformation poses a skeptical threat insofar as it undermines trust in even accurate information, thereby preventing true beliefs. Finally, misinformation poses an epistemic threat insofar as it degrades the evidential power of authentic content, introduces relevant alternatives, reduces the reliability of belief-forming processes, and makes it a matter of luck whether beliefs turn out to be true. It is argued that, while the deceptive threat of misinformation requires its actual existence, misinformation need not exist to pose both a skeptical and an epistemic threat. Finally, it is argued that attending to sources of information can reduce, but not eliminate, the three-pronged threat of misinformation.
