Mathematics is the key and door to the sciences. - Galileo Galilei

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.

I am certainly interested in a tribunal in which, for having used my reason, I was deemed little less than a heretic. Who knows but men will reduce me from the profession of a philosopher to that of historian of the Inquisition! But they behave to me in order that I may become the ignoramus and the fool of Italy...

I have never met a man so ignorant that I could not learn something from him.