The only real valuable thing is intuition. The intellect has little to do on the road to discovery

In any conflict between humanity and technology, humanity will win.

The longing to behold this pre-established harmony [of phenomena and theoretical principles] is the source of the inexhaustible patience and perseverance with which Planck has devoted himself ... The state of mind which enables a man to do work of this kind is akin to that of the religious worshiper or the lover; the daily effort comes from no deliberate intention or program, but straight from the heart.

Agreements about what is good or not, are usually not worth much. It is very much like art, is it not an art to lead a good life?

The fanatical atheists are like slaves who are still feeling the weight of their chains which they have thrown off after hard struggle. They are creatures who—in their grudge against traditional religion as the "opium of the masses"—cannot hear the music of the spheres.

I do not much believe in education. Each person ought to be his or her own model, however frightful that may be.

Imagination is the highest form of research.