Men are more evanescent than pictures, yet one sorrows for lost friends, and pictures are my friends. I have none others. I am never long enough with men to attach myself to them; and whatever feelings of attachment I have are to material things.

All the other passions do occasional good, but whenever pride puts in its word, everything goes wrong, and what it might really be desirable to do, quietly and innocently, it is mortally dangerous to do, proudly.

Science is the knowledge of constant things, not merely of passing events, and is properly less the knowledge of general laws than of existing facts.

When men are rightly occupied, their amusement grows out of their work.

God is a kind Father. He sets us all in the places where he wishes us to be employed. He chooses work for every creature which will be delightful to them if they do it simply and humbly. He gives us always strength enough and sense enough for what he wants us to do.

The work of science is to substitute facts for appearances, and demonstrations for impressions.

Without mountains the air could not be purified, nor the flowing of the rivers sustained.