THE AGE OF GENIUS

A British philosopher examines a century of profound intellectual change.

In this sweeping, lively historical survey, Grayling (Philosophy/New Coll. of the Humanities, London; The Challenge of Things: Thinking Through Troubled Times, 2015, etc.) argues vigorously that in the 17th century, an “age of strife and genius,” humankind experienced “the greatest ever change in…mental outlook.” Certainly the century was peopled by some major figures, including Descartes (the subject of one of Grayling’s biographies), Shakespeare, Cervantes, Milton, Hobbes, Spinoza, Pascal, Galileo, Newton, Rembrandt, and Vermeer. Besides giving an overview of their contributions, the author reveals how they interacted in the rich “republic of letters” in which they shared ideas. Letter writing, he contends, flourished because of the availability of cheap paper and both public and private postal services. Significant among the busy correspondents was a French Minim monk, Marin Mersenne, whom the author describes as “the seventeenth century’s closest thing to an internet server”—he corresponded with about 150 leading mathematicians, astronomers, and philosophers and fostered the sharing of their ideas. It was Mersenne, Grayling notes, who put Descartes together with Pascal. Also influential in disseminating ideas was the polymath Samuel Hartlib, who boasted nearly 500 correspondents across Europe, including Galileo, and wrote dozens of letters each day. Grayling sets the robust intellectual life against the politics of the day, which saw unrest, upheaval, and almost constant war. Only for three years was there no fighting; war was “the normal condition of the time; war was the wallpaper.” Nevertheless, war pushed scientific innovation as armies sought improved weaponry. Grayling examines scientific change more broadly, contrasting religious and occult perspectives on understanding nature with the rise of the scientific method. By the end of the century, faith had been repudiated as a method of inquiry.

Out of a “fractured and fractious time,” the author asserts persuasively, the medieval mind evolved into the modern. Another thought-provoking winner from Grayling.