In second language class, students will commonly face difficulties in thinking in the target language because they are influenced by their native language and culture patterns. Robert B. Kaplan thinks that in second language classes, the foreign-student paper is out of focus because the foreign student is employing rhetoric and a sequence of thought which violate the expectations of the native reader. Foreign students who have mastered syntactic structures have still demonstrated an inability to compose adequate themes, term papers, theses, and dissertations. Robert B. Kaplan describes two key words that affect people when they learn a second language. Logic in the popular, rather than the logician's sense of the word, is the basis of rhetoric, evolved out of a culture; it is not universal. Rhetoric, then, is not universal either, but varies from culture to culture and even from time to time within a given culture. Language teachers know how to predict the differences between pronunciations or constructions in different languages, but they might be less clear about the differences between rhetoric, that is, in the way they use language to accomplish various purposes, particularly in writing.