Now since in so many Things they... agree, what can be more probable than that in others they agree too and that the other Planets are as beautiful and as well stock'd with Inhabitants as the Earth? Or what shadow of Reason can there be why they should not?

These Gentlemen must be told, that they take too much upon themselves when they pretend to appoint how far and no farther Men shall go in their Searches, and to set bounds to other Mens Industry as if they knew the Marks that God has placed to Knowledge.

I had not thought of this regular decrease of gravity, namely that it is as the inverse square of the distance this is a new and highly remarkable property of gravity.

The world is my country. Science my religion.

Here we may mount from this dull Earth, and viewing it from on high, consider whether Nature has laid out all her Cost and Finery upon this small Speck of Dirt.

We shall be less apt to admire what this World calls Great, shall nobly despise those Trifles the generality of Men set their Affections on, when we know that there are a multitude of such Earths inhabited and adorned as Well as our own.

It's evident God had no design to make a particular Enumeration in the Holy Scriptures, of all the Works of his Creation.

I do not mind at all that Newton is not a Cartesian provided he does not offer us suppositions like that of attraction.

I do not believe anything very certainly, but everything very probably.

...great difficulties are felt at first and these cannot be overcome except by starting from experiments .. and then be conceiving certain hypotheses ... But even so, very much hard work remains to be done and one needs not only great perspicacity but often a degree of good fortune.