His best known book The Thirteenth, The Greatest of Centuries (1907) was required reading at Catholic colleges well into the 1960’s. Fordham historian Father Raymond Schroth, S.J., writes: “Today, in general parlance, the word medieval is often used to express opprobrium… as in ‘the living conditions were medieval’ or ‘medieval torture.” But Dr. Walsh saw in the Middle Ages the integration of faith and intellect, and the wisdom of that era offered principles on which a new world might be built. The growing secularism permeating modern life, he believed, had its roots in the Reformation and the breakdown of Christian unity. Walsh wasn’t the first to propose this, nor was his the final word on the subject. But he was enormously influential in his time, and he deserves credit for his role in helping to prompt the literary revival that dominated Catholic life in America and Europe in the years between the two world wars.