In 1946, in a small room in Cambridge, England, a routine meeting of the Kings College Moral Science Club may or may not have marked the apex of a half-century's worth of social and intellectual upheaval. Joining 30 or so students at the meeting were two famously combative giants of philosophy: Karl Popper and Ludwig Wittgenstein. Debating a paper titled "Are There Philosophical Problems?," they traded barbs, dismissed each other as misguided fools, and, in just 10 minutes, cemented their roles in a melodrama that would come to take on the mirth of myth. An alternately fascinating and overstretched meditation on history's ability to cling to arbitrary signposts, Wittgenstein's Poker opens by zooming in on the isolated incident of Wittgenstein waving a fireplace poker in Popper's face. Whether it was a threat or merely an oratorical flourish has been a hotly contested issue in academic circles ever since. Co-authors David Edmonds and John Eidinow, both BBC journalists, seem genuinely invested in the hilariously fussy antics of ideologues wrestling over different accounts of the so-called "poker incident." But as they pan out to investigate the story, the authors sift through the gossip and reveal the meeting of Popper and Wittgenstein as a culmination of weighty tide-shifts in 20th-century Western civilization. Born to assimilated Jewish families in coffeehouse-crazed fin de siècle Vienna, both men went on to affect philosophy in profoundly different ways. Wittgenstein, raised in an aristocratic household central to Vienna's cultural and intellectual golden age, became a mystically revered figure for his work in symbolic logic. The big questions in philosophy, according to Wittgenstein, were little more than byproducts of language. In his analytic system, introduced in his 1921 masterwork Tractatus Logico-Philosophicus, the key to navigating the space between sense and nonsense lies in understanding the linguistic structures that dictate knowledge. Named alongside Albert Einstein and Bertrand Russell as an intellectual father of the vaunted Vienna Circle, Wittgenstein was a notoriously difficult eccentric whose "unearthly, almost alien" personality only helped his standing as a visionary genius. He was also a major thorn in the side of self-styled outsider Popper, a more concrete-oriented philosopher who resented Wittgenstein's privileged upbringing and spent his life obsessively deriding "logical positivism" as a trifling puzzle game. Wittgenstein's Poker does a marvelous job of tracing the two figures' related histories, from the early Vienna days through the onset of Nazi occupation and the world-tilting ravages of war. Poker's premise occasionally buckles under the authors' tendency to undersell the bristling conflict in their subjects' work in favor of less significant personal details. But when Popper and Wittgenstein come face to face for the first time at the fateful debate in 1946, with a nearly 50 years of confluence illuminated behind them, the subjective swirl of history takes on a life of its own.