It can be assumed that the abuse given to Buck by the man in the sweater was so severe that it made him forget the good man had done for him and that it was better to be a wild animal than a domesticated one. It could possibly be that Buck may have thought that John was no different than the man in the sweater and as he is moved from owners, his view of humans is changed. .
The "man in the sweater's" use of a club changes Buck forever. As the narrator states: "He had learned the lesson, and in all his afterlife he never forgot it. That club was a revelation. It was his introduction to the reign of primitive law, and he met the introduction halfway. The facts of life took on a fiercer aspect; and while he faced that aspect uncowed, he faced it with all the latent cunning of his nature aroused. As the days went by, other dogs came, in crates and at the ends of ropes, some docilely, and some raging and roaring as he had come; and, one and all, he watched them pass under the dominion of the man in the red sweater. Again and again, as he looked at each brutal performance, the lesson was driven home to Buck: a man with a club was a lawgiver, a master to be obeyed, though not necessarily conciliated" (London, 6).
Buck had learned from the brutal man in the sweater of what he was to face and it could possibly have been his doing that changed Buck so drastically. If Buck hadn't been abused so severely it could have made the argument about Buck's feelings for John one-sided, with Buck giving thanks to John for saving him and keeping him from becoming a ferocious animal. In conclusion, the biggest influence on what Buck and John's relationship is based on is the man in the sweater and his brutish ways. Perhaps Buck's search for a good owner such as John is just a way to redeem the injustice he received from the man in the sweater. When Buck is sold to Francois and Perrault, there is hope that Buck may finally go to a loving home.
