Ludwig Wittgenstein, one of the most influential philosophers of the 20th century, only published one book during his life: Tractatus Logico-Philosophicus (1921). But what a book! It posits that the origin of philosophical problems are in the logic of language and misunderstandings of that logic. This exhibition, hosted in the city where Wittgenstein lived and worked, isn’t concerned with the book for which he is famous. Instead, the focus moves to his lesser-known interest in photography. Born in 1889, into a family that was influential in the Viennese art world, Wittgenstein took photographs and collected them. The show includes images of the Wittgenstein family, as well as the philosopher’s staged self-portraits. And for the first time, Wittgenstein’s 1930s photo album is displayed in full. —J.D.