"What goes up must come down."

"The light which comes from the sun, and from all fire, consists of all the primary colours mixed together."

"To explain all nature is too difficult a task for any one man or even for any one age."

"I was born in the year of the comet."

"He who thinks half-heartedly will not believe in God; but he who thinks seriously will believe in God, and will not doubt that God is the author of the world."