Philosophy is written in this grand book, the universe, which stands continually open to our gaze. But the book cannot be understood unless one first learns to comprehend the language and read the letters in which it is composed.
We cannot teach people anything; we can only help them discover it within themselves.
I have never met a man so ignorant that I couldn’t learn something from him.
He who looks the higher is the more highly distinguished, and turning over the great book of nature (which is the proper object of philosophy) is the way to elevate one’s gaze.
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.
All truths are easy to understand once they have been revealed. What is difficult is to discover them.
See now the power of truth; the same experiment which at first glance seemed to show one thing, when more carefully examined, assures us of the contrary.
The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.
By denying scientific principles, one may maintain any paradox.
I have been in my bed for five weeks, oppressed with weakness and other infirmities from which my age, seventy four years, permits me not to hope release. Added to this (proh dolor! [O misery!]) the sight of my right eye — that eye whose labors (dare I say it) have had such glorious results — is for ever lost. That of the left, which was and is imperfect, is rendered null by continual weeping.
Names and attributes must be accommodated to the essence of things, and not the essence to the names, since things come first and names afterwards.
It vexes me when they would constrain science by the authority of the Scriptures, and yet do not consider themselves bound to answer reason and experiment.
My dear Kepler, what would you say of the learned here, who, replete with the pertinacity of the asp, have steadfastly refused to cast a glance through the telescope? What shall we make of this? Shall we laugh, or shall we cry?
I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use.