The passion for seeking the truth for truth's sake can be kept alive only if we continue to seek the truth for truth's sake.

My father had retained an emotional affection for the ceremonial of his parental home, without allowing it to influence his intellectual freedom

Remember that in every single case in history the process of adaptation has been one of exceeding slowness. Do not look for the impossible, but do not let your path deviate from the quiet and steadfast insistence on full opportunities for your powers.

No one has ever proved that a human being, through his descent from a certain group of people, must of necessity have certain mental characteristics.

We all know scientists who in private life do not come up to the standard of truthfulness, but who, nevertheless, would not consciously falsify the results of their researches

The disease of mutual distrust among nations is the bane of modern civilization

Furthermore, the study of the present surroundings is insufficient: the history of the people, the influence of the regions through which it has passed on its migrations, and the people with whom it came into contact, must be considered