Answer: The last word of Keesh was "It is not for a boy to know about witches, and I know nothing about witches. I only have means whereby I may kill an ice-bear with ease, that's all. It would be headcraft, not witchcraft".
In "The Story of Keesh" by Jack London, the people of the tribe did not believe that Keesh had hunt a large polar bear by himself, so they accused him and his mother of witchcraft. It required dignity and manhood for him to defend himself and speak against the elder hunters who disliked him.
By saying that, he indicates that they know each other very well and that without talking, they have similar ideas and outlooks on the world in response to certain situations.
Someone or something alive and able to think or feel
I think this might help you figure out the theme, hope this helps