Sum is exactly what is says it is: forty two-or-three page stories about different versions of the afterlife, all told in the second person. In one story, your friends are the only people who made it to heaven; in another story, God is immense. In another story, God is a microbe who doesn't know we exist. In the first story, "all the moments [of your life] that share a quality are grouped together."

But that doesn't mean it's always pleasant. You spend six days clipping your nails. Fifteen months looking for lost items. Eighteen months standing in line. Two years of boredom: staring out a bus window, sitting in an airport terminal. One year reading books. Your eyes hurt, and you itch, because you can't take a shower until it's your time to take your marathon two-hundred-day shower. Two weeks wondering what happens when you die.

They're tiny, accessible philosophical thought experiments. Eagleman runs a neuroscience laboratory as a day job, and his interests include synesthesia and time perception. The writing can occasionally get a bit clunky and some stories are necessarily more pointless than others, but Sum is a lovely book, reminiscent of Calvino's Cosmicomics. And despite the spiritual subject matter, this is a book that athiests and agnostics can enjoy (Philip Pullman blurbs the book, in case you needed comfort from a Famous Atheist).

It's the kind of book you can sit with on a Sunday afternoon, reading a piece, putting down the book and staring out the window for a while before dipping back in. Check it out at a library or bookstore; read a piece at random and you'll probably know immediately whether this is the kind of book you'll enjoy. I loved it.