Do not consider it proof just because it is written in books, for a liar who will deceive with his tongue will not hesitate to do the same with his pen. They are utter fools who accept a thing as convincing proof simply because it is in writing.

Maimonides (1135-1204) Spanish Jewish philosopher, scholar, astronomer, physician [Moses ben Maimon, Rambam, רמב״ם]

Iggeret Teman, “Responsa”