A Vulgar Mechanick can practice what he has been taught or seen done, but if he is in an error he knows not how to find it out and correct it, and if you put him out of his road he is at a stand. Whereas he that is able to reason nimbly and judiciously about figure, force, and motion, is never at rest till he gets over every rub. (from a letter dated 25 May, 1694)

The qualities of bodies, which admit neither intension nor remission of degrees, and which are found to belong to fill bodies within the reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever.

As a blind man has no idea of colors, so we have no idea of the manner by which the all-wise God perceives and understands all things.

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.

He that in ye mine of knowledge deepest diggeth, hath, like every other miner, ye least breathing time, and must sometimes at least come to terr. alt. for air.

In the absence of any other proof, the thumb alone would convince me of God's existence.

This thing is but a puny imitation of a much grander system whose laws you know, and I am not able to convince you that this mere toy is without a designer or maker; yet you profess to believe that the great original from which the design is taken has come into being without either designer or maker! Now tell me by what sort of reasoning do you reach such an incongruous conclusion?