“Misfortune shows those who are not really friends.”

“Poetry is finer and more philosophical than history; for poetry expresses the universal, and history only the particular.”

“The greatest thing by far is to have a command of metaphor. This alone cannot be imparted by another; it is the mark of genius, for to make good metaphors implies an eye for resemblances.”

“A friend is one soul abiding in two bodies.”

“Hope is the dream of a waking man.”

“The least initial deviation from the truth is multiplied later a thousandfold.”

“Geometry was invented that we might expeditiously avoid, by drawing Lines, the Tediousness of Computation.”

“I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.”

“Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments.”

“There is a fundamental difference between religion, which is based on authority and science, which is based on observation and reason. Science will win, because it works.”

“My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.”

“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.”