These books reveal why the brain is the biggest mystery of all

THE HUMAN brain—the enigmatic organ of thought—is the most intricate object in the universe, a tangled orchestra of hundreds of billions of cells generating precise electrical impulses that make up a mental symphony. Understanding how these harmonies conjure thoughts, memories and emotions is perhaps the greatest scientific question of all—the brain seeking to understand itself—and yet the question remains unanswered after 150 years of investigation by many of the best brains. Fortunately, they have made some progress. These books elegantly summarise what is (and is yet to be) known about brains.

The father of neuroscience—Santiago Ramón y Cajal, a Spanish histologist—may not enjoy the fame of other 19th-century giants like Charles Darwin and Louis Pasteur, but his achievements make him their equal. Over 30 years, based in Barcelona and then in Madrid, Cajal greatly improved the staining technique invented by his rival Camillo Golgi, with whom he shared a Nobel prize in 1906. This made nerve cells visible under a microscope, revealing the brain’s structure in unprecedented detail. Cajal showed that neurons are independent cells, settling the bitterest debate in microbiology of his lifetime. And he predicted the course of more than a century of subsequent scientific work.