Yu believes the May Fourth intellectuals had only a limited understanding of the Western concepts of liberty, democracy, and human rights, and also lacked firsthand knowledge of working-class society. Fervently desiring reform, they were ultimately drawn to Marxism.
余英時認為，五四知識分子對西方的自由、民主、人權等概念所知有限，也缺乏對基層民間社會現實的理解，因此滿腔熱血終被馬克思主義的狂潮襲去。