1765-1822

Italian Mathematician and Physician

The Abel-Ruffini theorem states that quintic equations, or algebraic equations greater than the fourth degree, cannot be solved using only radicals—i.e., square roots, cube roots, and other roots. It is named after Niels Henrik Abel (1802-1829) and Paolo Ruffini, whose findings Abel confirmed. Ruffini also contributed to the development of group theory, and was known for his work as a philosopher and physician.

When Ruffini was born on September 22, 1765, his hometown of Valentano was a part of the Papal States, a geopolitical entity on the Italian peninsula that had existed for a thousand years. His own lifetime, however, would witness political upheaval that brought the existence of the states to a temporary end under the invading forces of Napoleon Bonaparte. While he was a teenager, his parents—Basilio, a physician, and Maria Ippoliti Ruffini—moved the family to Modena...