A good video explaining this Latin saying. The saying "Nullius in verba" means "On no one's word."
It is a call to put evidence, data, and experimentation to be the final authority on explanations of natural phenomena, and not because "someone" says so. That someone can be anyone - someone with the religious OR political OR even, scientific, authority. In the hierarchy of the process to search for the truth, it is only the facts that must matter, nothing else.
It is fitting that the Royal Society chose this pithy saying as its motto.
Watch the video here.
