This action happens, of course, in Chapter 15.
Bernard and Helmholtz are at Helmholtz's apartment when a friend of Watson's calls to tell him that John the Savage is involved in the brawl at the hospital.
The two men go to the hospital, but then they react very differently. Helmholtz is exultant. He jumps in and starts punching and fighting along with John. By contrast, Bernard appeals to the police for help.
I think this shows how Bernard is much less of a rebel than Helmholtz is. Bernard really just wants his life to be easy. Helmholtz truly wants to rebel.
We'll see a similar thing when Mond tells the two men what's going to happen to them. Watson takes it well, but Bernard has to be sedated.