Why Does the World Exist?: An Existential Detective Story by Jim Holt Liveright, 307 pp., $27.95

Jim Holt’s Why Does the World Exist?: An Existential Detective Story is a portrait gallery of leading modern philosophers. He visited each of them in turn, warning them in advance that he was coming to discuss with them a single question: “Why is there something rather than nothing?” He reports their reactions to this question, and embellishes their words with descriptions of their habits and personalities. Their answers give us vivid glimpses of the speakers but do not solve the riddle of existence.

The philosophers are more interesting than the philosophy. Most of them are eccentric characters who have risen to the top of their profession. They think their deep thoughts in places of unusual beauty such as Paris and Oxford. They are heirs to an ancient tradition of academic hierarchy, in which disciples sat at the feet of sages, and sages enlightened disciples with Delphic utterances. The universities of Paris and Oxford have maintained this tradition for eight hundred years. The great world religions have maintained it even longer. Universities and religions are the most durable of human institutions.

According to Holt, the two most influential philosophers of the twentieth century were Martin Heidegger and Ludwig Wittgenstein, Heidegger supreme in continental Europe, Wittgenstein in the English-speaking world. Heidegger was one of the founders of existentialism, a school of philosophy that was especially attractive to French intellectuals. Heidegger himself lost his credibility in 1933 when he accepted the position of rector of the University of Freiburg under the newly established Hitler government and became a member of the Nazi Party. Existentialism continued to flourish in France after it faded in Germany.

Wittgenstein, unlike Heidegger, did not establish an ism. He wrote very little, and everything that he wrote was simple and clear. The only book that he published during his lifetime was Tractatus Logico-Philosophicus, written in Vienna in 1918 and published in England with a long introduction by Bertrand Russell in 1922. It fills less than two hundred small pages, even though the original German and the English translation are printed side by side. I was lucky to be given a copy of the Tractatus as a prize when I was in high school. I read it through in one night, in an ecstasy of adolescent enthusiasm. Most of it is about mathematical logic. Only the last five pages deal with human problems. The text is divided into numbered sections, each consisting of one or two sentences. For example, section 6.521 says: “The solution of the problem of life is seen in the vanishing of this problem. Is not this the reason why men, to whom after long doubting the sense of life became clear, could not then say wherein this sense consisted?” The most famous sentence in the book is the final section 7: “Wherof one cannot speak, thereof one must be silent.”

I found the book enlightening and liberating.…