Respectfully Quoted: A Dictionary of Quotations. 1989.
| NUMBER: | 1096 |
| AUTHOR: | Karl Augustus Menninger (1893–1990) |
| QUOTATION: | Unrest of spirit is a mark of life; one problem after another presents itself and in the solving of them we can find our greatest pleasure. |
| ATTRIBUTION: | |
| SUBJECTS: | Life |