Why are we so fascinated by monsters? On Monsters by Columbia College philosophy professor Stephen Asma offers some tentative and mostly pro forma answers drawn from evolution, psychology, sociology, and history. Really, though, the book is less focused on explaining our interest than capitalizing on it. Asma has a lucid, engaging style, and he uses it to provide a thoughtfully breezy survey of the bizarre and the lurking. Did you know ancient griffins may have been inspired by protoceratops bones? That medieval witches were reputed to cut off penises and keep them in boxes, where the severed organs supposedly snuffled around and fed like little rodents? That the Japanese have been perfecting cyborg roaches? There’s a worthwhile factoid like that on almost every other page. From polite but satisfyingly lurid retellings of horrific true-life crimes to photographic images of grotesque fetal deformities, On Monsters has something for every adorer of the outre. And when you’re done, despite the lack of concrete answers, the whys and wherefores of monsters do seem less opaque. I mean, blood, evil, twisted flesh, apocalypse—what’s not to like? —Noah Berlatsky