Necessity is the mother of invention.
No man's knowledge here can go beyond his experience.
What is now proved was once only imagined.
Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.
Science is not only a disciple of reason but, also, one of romance and passion.
The highest activity a human being can attain is learning for understanding, because to understand is to be free.
Courage, conviction and confidence.
A cynic is a man who knows the price of everything, and the value of nothing.
Action not backed by knowledge and knowledge not translatable into action, both can not stand the test of time.
Patience is a virtue, and I'm learning patience. It's a tough lesson.
There is no authority who decides what is a good idea.
To read is to fly: it is to soar to a point of vantage which gives a view over wide terrains of history, human variety, ideas, shared experience and the fruits of many inquiries.
I prefer the company of peasants because they have not been educated sufficiently to reason incorrectly.
The only true wisdom is in knowing you know nothing.
Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.
All stable processes we shall predict. All unstable processes we shall control.
Don't learn to do, but learn in doing.
Opinion is the medium between knowledge and ignorance.
Education is a human right with immense power to transform. On its foundation rest the cornerstones of freedom, democracy and sustainable human development.
There is one quality which one must possess to win, and that is definiteness of purpose, the knowledge of what one wants, and a burning desire to possess it.
Real knowledge is to know the extent of one's ignorance.