How we cite our quotes: (Chapter.Paragraph) Shmoop has numbered the chapters continuously, but the book renumbers them in each Part.
Quote #4
Tied securely, White Fang could only rage futilely and endure the punishment. Club and whip were both used upon him, and he experienced the worst beating he had ever received in his life. Even the big beating given him in his puppyhood by Grey Beaver was mild compared with this. (16.23)
Grey Beaver gives way to Beauty Smith and the marathon of agonizing torment is on. Everything about Beauty causes pain to White Fang, putting this section clear in the "suffering is bad" column.
Quote #5
Under the tutelage of the mad god, White Fang became a fiend. (17.1)
London here seems to be saying that suffering doesn't just hurt the person who suffers. It makes that person a monster who will go on hurting others. And just to prove our point, scroll on down to the next quote to see what we have to say.
Quote #6
In short, Beauty Smith was a monstrosity, and the blame of it lay elsewhere. He was not responsible. The clay of him had been so moulded in the making. (16.7)
So Beauty suffers just like White Fang did, and in turn makes White Fang suffer, who makes the dogs he fights suffer and so on. It's the great circle of life, only really, really evil.