All sorrow has its root in man's inability to sit quiet in a room by himself.

Let each of us examine his thoughts; he will find them wholly concerned with the past or the future. We almost never think of the present, and if we do think of it, it is only to see what light is throws on our plans for the future. The present is never our end. The past and the present are our means, the future alone our end. Thus we never actually live, but hope to live, and since we are always planning how to be happy, it is inevitable that we should never be so.

Eloquence is a painting of thought; and thus those who, after having painted it, add something more, make a picture instead of a portrait.

To doubt is a misfortune, but to seek when in doubt is an indispensable duty. So he who doubts and seeks not is at once unfortunate and unfair.

Dull minds are never either intuitive or mathematical.

The secrets of nature are concealed; her agency is perpetual, but we do not always discover its effects; time reveals them from age to age; and although she is always the same in herself, she is not always equally well known.

Brave deeds are wasted when hidden.