The first forty years of our life give the text, the next thirty furnish the commentary upon it, which enables us rightly to understand the true meaning and connection of the text with its moral and its beauties.
The fountain of content must spring up in the mind, and he who has so little knowledge of human nature as to seek happiness by changing anything but his own disposition will waste his life in fruitless efforts, and multiply the griefs which he purposes to remove.
The further the spiritual evolution of mankind advances, the more certain it seems to me that the path to genuine religiosity does not lie through the fear of life, and the fear of death, and blind faith, but through striving after rational knowledge.
The future of humanity is uncertain, even in the most prosperous countries, and the quality of life deteriorates; and yet I believe that what is being discovered about the infinitely large and infinitely small is sufficient to absolve this end of the century and millennium. What a very few are acquiring in knowledge of the physical world will perhaps cause this period not to be judged as a pure return of barbarism.