Where there is most labour there is not always most life.

The immense value of becoming acquainted with a foreign language is that we are thereby led into a new world of tradition and thought and feeling.

Reproduction is so primitive and fundamental a function of vital organisms that the mechanism by which it is assured is highly complex and not yet clearly understood. It is not necessarily connected with sex, nor is sex necessarily connected with reproduction.

Still, whether we like it or not, the task of speeding up the decrease of the human population becomes increasingly urgent.

No faith is our own that we have not arduously won.

Imagination is a poor substitute for experience.

However well organised the foundations of life may be, life must always be full of risks.