Any power must be an enemy of mankind which enslaves the individual by power and by force, whether it arises under the Fascist or the Communist flag. All that is valuable in human society depends upon the opportunity for development accorded to the individual.

E=mc2. Energy equals mass times the speed of light squared

I think and think for months and years. Ninety-nine times, the conclusion is false. The hundredth time I am right.

I think we have to safeguard ourselves against people who are a menace to others, quite apart from what may have motivated their deeds.

The majority of the stupid is invincible and guaranteed for all time. The terror of their tyranny, however, is alleviated by their lack of consistency.

The aim (of education) must be the training of independently acting and thinking individuals who, however, see in the service to the community their highest life problem.

It is, in fact, nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom; without this it goes to wrack and ruin without fail. It is a grave mistake to think that the enjoyment of seeing and searching can be promoted by means of coercion and a sense of duty.