21. Without the ability to think critically, to defend their ideas and understand the ideas of others, they cannot fully participate in our democracy.

【分析】简单句。句首介词短语without…others作条件状语，其中the ability后跟不定式短语to think critically, to defend their ideas and understand the ideas of others作其后置定语；句子的主语为they,谓语为cannot fully participate in，宾语为 our democracy。
【译文】如果没有能力进行批判性思维，维护自己的观点，并理解他人的观点，他们就不能充分地参与到我们的民主政治中来。

22. "Intellect is resented as a form of power or privilege," writes historian and professor Richard Hofstadter in Anti-Intellectualism in American Life, a Pulitzer-Prize winning book on the roots of anti-intellectualism in US politics, religion, and education.

【分析】句子主干为一个完全倒装句。谓语writes放在主语historian and professor Richard Hofstadter 之前；宾语为直接引语。in Anti-Intellectualism in American Life作状语，斜体部分为书名，后面a Pulitzer-Prize inning book...是其同位语。
【译文】“才智被人们看作一种权力或特权而遭到憎恶，”历史学家理查德·霍夫斯塔特教授在他的《美国社会中的反才智主义》—书中这样写道。这本曾获普利策奖的书探讨了美国政治、宗教和教育中的反才智主义的根源。
【点拨】本句中on是“关于，以…为主题”的意思。