If you find from your own ...

If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.
If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.

Quotes from the same author

All our knowledge has its origins in our perceptions.
It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.
Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind.
Nothing strengthens authority so much as silence.
He who is fixed to a star does not change his mind.