His approach worked well in the increasingly mature business world of the second half of the twentieth century. By that time large corporations had developed the basic manufacturing efficiencies and managerial hierarchies of mass production. Executives thought they knew how to run companies, and Drucker took it upon himself to poke holes in their beliefs, lest organizations become stale. But he did so in a sympathetic way. He assumed that his readers were intelligent, rational, hardworking people of good will. If their organizations struggled, he believed it was usually because of outdated ideas, a narrow conception of problems, or internal misunderstandings.