condemned criminals on their way to execution in order to study and sketch in his notebook their features, distorted by fear, nor did it prevent him from inventing the most cruel offensive weapons, and from entering the service of Cesare Borgia as chief military engineer. Often he seemed to be indifferent to good and evil, or he had to be measured with a special standard. He held a high position in Cesare's campaign which gained for this most inconsiderate and most faithless of foes the possession of the Romagna. Not a single line of Leonardo's sketches betrays any criticism or sympathy of the events of those days. The comparison with Goethe during the French campaign cannot here be altogether rejected.
If a biographical effort really endeavors to penetrate the understanding of the psychic life of its hero it must not, as happens in most biographies through discretion or prudery, pass over in silence the sexual activity or the sex peculiarity of the one examined. What we know about it in Leonardo is very little but full of significance. In a period where there was a constant struggle between riotous licentious-
