"Do not believe in anything simply because you have heard it,
do not believe in traditions because they have been handed down for many generations,
do not believe in anything because it is spoken and rumoured by many,
do not believe in anything simply because it is written in your religious books,
do not believe in anything merely on the authority of your teachers and elders.
But after observation and analysis, when you find something that agrees
with reason and is conductive to the good and benefit of one and all,
then accept it and abide by it."

The Buddha, in "The Kalama Sutra"