Four German-speaking philosophers in search of a theme

How do you write a group biography of people who never actually formed a group? Such is the challenge Wolfram Eilenberger sets himself in a book about the philosophers Martin Heidegger, Ludwig Wittgenstein, Walter Benjamin and — the surprisingly unstarry fourth subject — Ernst Cassirer, an urbane and now nearly forgotten neo-Kantian who might have deserved the made-up title of ‘symbologist’, thus far reserved for the heroes of Dan Brown’s novels. What these men have in common is that they spoke German and were philosophically active during the 1920s, but that is about it. Heidegger and Cassirer met and traded rhetorical blows at a celebrated philosophy conference in Davos; Benjamin

Let’s leave philosophers to puzzle over the reality of numbers

The reality (or lack thereof) of numbers is the kind of problem some philosophers consider overwhelmingly important, but it’s of no consequence to just about everyone else. It does not make a wink of difference to your life whether the figures in your bank account or the digits on your clock are, in a philosophical sense, really real, so long as they work as expected. The mathematician Paolo Zellini’s book, now translated by Simon Carnell and Erica Segre from the 2016 Italian original, does not exactly elevate the number-reality problem to a matter of concern to non-philosophers, and certainly does not explain the problem in a way that will make