To every action there is always opposed an equal reaction.
We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.
A man may imagine things that are false, but he can only understand things that are true, for if the things be false, the apprehension of them is not understanding.
To myself I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me.
If I have seen further than others, it is by standing upon the shoulders of giants.
If I have seen farther than others, it is because I was standing on the shoulders of giants.
I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
Errors are not in the art but in the artificers.
If I have done the public any service, it is due to my patient thought.
I can calculate the motion of heavenly bodies, but not the madness of people.
It is the weight, not numbers of experiments that is to be regarded.
We build too many walls and not enough bridges.
To me there has never been a higher source of earthly honor or distinction than that connected with advances in science.
Tact is the art of making a point without making an enemy.