Absolute, true, and mathematical time, in and of itself and of its own nature, without reference to anything external, flows uniformly and by another name is called duration. Relative, apparent, and common time is any sensible and external measure (precise or imprecise) of duration by means of motion; such as a measure-for example, an hour, a day, a month, a year-is commonly used instead of true time.

I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.

What goes up must come down.

Now the smallest Particles of Matter may cohere by the strongest Attractions, and compose bigger Particles of weaker Virture.... There are therefore Agents in Nature able to make the Particles of Bodies stick together by very strong Attraction. And it is the Business of experimental Philosophy to find them out.

If two angels were sent down from heaven -one to conduct an empire and the other to sweep the streets -they would feel no inclination to change employment because an angel would know that no matter what we are doing, it's an opportunity to bring joy, deepen our understanding and expand our life.

Every action has an equal and opposite reaction

I am ashamed to tell you to how many figures I carried these calculations [of Pi], having no other business at the time