If one reason Why Homer Matters (John Macrae, $30) is his unblinking presentation of the realities of war and heroism, loyalty and grief, another is “for the sake of the singing hereafter,” and Adam Nicolson’s heartfelt and illuminating book is surely in that lyrical heritage. Describing Homer as “the human spirit on fire,” and the epics as having been “invented after memory and before history,” Nicolson follows that spirit through a wide range of times, landscapes, cultures, and languages; he’s assembled a rich composite picture of the Homeric tradition, one that’s as personal as it is scholarly. Having bonded most fiercely with the Ancient while sailing, Nicolson embarks on a fascinating look at the sea in Homer’s poetry. Similarly, he traces the roles of horses, metals, and storytelling—which raises a host of age-old questions: where did Homer’s stories originate? And when? Are they products of stock formulas, improvised performances, or both? And was “Homer” one or many? Nicolson surveys the theories. He also looks at various timelines for Homer’s work, and, using linguistic, archeological, and cultural evidence, dates the poet back to the Bronze Age—further in the past than many critics do—with intriguing glimpses of a pre-Greek “subconscious,” from when Homer’s people inhabited the landlocked Eurasian steppes, circa 3000 BC.