Good and bad are not opposites - good is the mean between excess or deficiency. So between rashness and cowardice lies courage or boldness, between miserliness or profligacy lies generosity.
Mill and Utilitarianism
The best acts produce the most happiness, but to restrain hedonism and selfish personal happiness different pleasures had different values. The problem is that this leads to intellectual snobbery. The problem of high art that you can see in James Martin's book.
A runaway railway trolley will kill five people if it continues down the track or one person if it goes down the alternative track. Should we change the signal? That by a simple calculus of utility suggests we should switch the tracks. What about if the one person is a world famous neurosurgeon? Now imagine there is a bridge over the track with a large man and you can stop the trolley by pushing the large man onto the track and save the five. Should you push them?