Lennox thinks that Macbeth is a murderer, and that Fleance and Duncan's sons are innocent of the rumors that they killed their own fathers.
"Lennox does not believe either had anything to do with the deaths of their fathers. Macbeth has stolen Malcolm’s birthright to be king and Malcolm is in England trying to secure an army to gain his birthright back. Macduff has gone to join in his effort. Lennox and the Lord hope that Malcolm will be successful in restoring peace to Scotland."