Question: Frank B. McMahon wrote one of the first psychology textbooks to feature a light and easily readable style. He also included slang and examples that appealed to a youthful student market. Charles G. Morris wrote a psychology textbook that copied McMahon's style. Has Morris infringed McMahon's copyright? Strategy: McMahon cannot copyright an idea, only the expression of an idea. (See the "Result" at the end of this section.)