The right to search for truth implies also a duty.

The series of integers is obviously an invention of the human mind, a self-created tool which simplifies the ordering of certain sensory experiences.

Strenuous intellectual work and the study of God's Nature are the angels that will lead me through all the troubles of this life with consolation, strength, and uncompromising rigor.

Solitude is painful when one is young, but delightful when one is more mature.

The bitter and the sweet come from the outside, the hard from within, from one's own efforts.

Science will stagnate if it is made to serve practical goals.

Highly developed spirits often encounter resistance from mediocre minds.