Prince of Foxes1949

Cesare Borgia:
[Describing a man who would fit his requirements as an agent]... be as quick at deceit as a fox. He must have the grace of a dancer; the wrist of an assassin. He must have little regard for good faith, yet by his astuteness, be able to confuse men's minds. He must have confidence in himself, yet not let that confidence render him incautious. He must charm as a snake charms a bird, yet he must make no friends, except those who can be of use to him and, for the same reason, although he may make use of love, he must not love."