He had two favorite sayings: "No man is as bad as he seems to his worst enemy." "No man is as good as he seems to his best friend." His own faults he knew perfectly well to be quickness of temper and a proneness to hasty action.

Throughout his life he fought against them and he took as his models Willet and Tayoga, who always appeared to him to have a more thorough command over their own minds and impulses than any other men he ever knew.
Aside from his brilliancy and power in public life, Lennox had other qualities that distinguished him as a man.

He was noted for his cosmopolitan views concerning human affairs.

He had an uncommon largeness and breadth of vision, all the more notable then, as America was, in many respects, outside the greater world of Europe.

People in speaking of him, however, recalled the extraordinary variety and intensity of his experiences.