Bonaparte can be considered naive because he truly did like the English soldiers. He is naive because he was not able to see that his mission and his subjective feelings for the captured are two different realities. He is naive in forgetting that a mission is there, something that will overcome his feelings of affection.
A case can also be made that Bonaparte is naive because he does not stand up for his beliefs. He is naive because he expresses that he does not want to do his duty, but does so anyway. This reflects some type of misplaced confirmation that his duty will alleviate the emotional discomfort he experiences. His naivete is evident in how he goes ahead with what he knows to be wrong and thus causing him to experience a feeling that "anything that happened to me afterward, I never felt the same about again.’’ Bonaparte can be seen as naive in his inability to recognize that carrying out his mission will carry extreme emotional consequences, elements that will stay with him the rest of his days.