John Thornton is a character from the novel "The Call of the Wild," written by Jack London. He is a kind and compassionate man who becomes the owner of Buck, a domesticated dog that is forced to adapt to the harsh realities of life in the Yukon during the Klondike Gold Rush. Thornton's gentle nature and strong bond with Buck highlight themes of loyalty and friendship. In the story, John Thornton is portrayed as a skilled and experienced outdoorsman. He treats Buck with respect and love, contrasting sharply with the cruelty of other characters. Thornton's character represents the ideal of human kindness and the deep connection that can exist between humans and animals.