Grace is given of God, but knowledge is bought in the market.
If a little knowledge is dangerous - where is the man who has so much as to be out of danger?
We owe almost all our knowledge not to those who have agreed, but to those who have differed.
Sit down before fact as a little child, be prepared to give up every preconceived notion, follow humbly wherever and to whatever abyss nature leads, or you shall learn nothing.
The learned is happy, nature to explore, the fool is happy, that he knows no more.
One of the greatest joys known to man is to take a flight into ignorance in search of knowledge.
I do not pretend to know what many ignorant men are sure of.
A man only understands what is akin to something already existing in himself.
Everybody gets so much common information all day long that they lose their common sense.
Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps learning stays young. The greatest thing in life is to keep your mind young.
The first problem for all of us, men and women, is not to learn, but to unlearn.
We should live and learn; but by the time we've learned, it's too late to live.
The specialist is a man who fears the other subjects.
All that men really understand is confined to a very small compass; to their daily affairs and experience; to what they have an opportunity to know; and motives to study or practise. The rest is affectation and imposture.
There is much pleasure to be gained from useless knowledge.
Every great advance in natural knowledge has involved the absolute rejection of authority.
It isn't what we don't know that gives us trouble, it's what we know that ain't so.
In all affairs, love, religion, politics or business, it's a healthy idea, now and then, to hang a question mark on things you have long taken for granted.
Knowledge is power.
Man is not weak - knowledge is more than equivalent to force. The master of mechanics laughs at strength.