In 1668, Thomas Hobbes argued that university education fueled the religious and political radicalism leading to the English Civil War (1642–1651). We revisit this thesis, further substantiated by Stone (1964) and Curtis (1962), and empirically test whether the educational expansion in early modern England created “alienated intellectuals” who, frustrated by limited job prospects, published radical ideas. Using novel datasets of 60,000 university students, 800 grammar schools, clerical job openings (CCEd), and published titles (ESTC), we explore how educational expansion affected social mobility, labour market outcomes, and radicalization. Grammar school foundations increased university enrollments by 10–20%, particularly benefiting poorer students. However, poorer graduates faced barriers to upward mobility, with many confined to precarious, low-income positions. Employing machine learning and instrumental variable analysis, we show that poor job outcomes significantly increased the likelihood of publishing radical ideas, supporting Curtis’s hypothesis that education-induced frustrations contributed to political instability.