“Homer has become a kind of scripture for me, an ancient book, full of urgent imperatives and ancient meanings, most of them half discerned, to be puzzled over. It is a source of wisdom.” So begins the third chapter of Adam Nicolson’s highly accessible new book, “Why Homer Matters,” in which he compares his relationship with epic poetry to a form of possession, a “colonization of the mind by an imaginative presence from the past.” The world needs more Adam Nicolsons, unabashedly passionate evangelists for the power of ancient poetry to connect us with our collective past, illuminate our personal struggles and interrogate our understanding of human history.

For centuries, the study of Greek literature has been seen as the province of career academics. But Nicolson’s amateurism (in the best, etymological, sense of the word: from the Latin amare, “to love”) and globe-trotting passion for his subject is contagious, intimating that it is impossible to comprehend Homer’s poems from an armchair or behind a desk. If you’ve never read the “Iliad” or the “Odyssey,” or your copies have been collecting dust since college, Nicolson’s book is likely to inspire you to visit or revisit their pages.

According to Nicolson, a British baron who has written books on subjects that span the making of the King James Bible, the challenges and joys of farming, nautical voyages, and long walks through France, “you don’t acquire Homer; Homer acquires you.” Nicolson describes how he set out on a personal odyssey from the coast of Scotland to the gates of Hades in search of the origins of Greek poetry and Western consciousness. In all of this, he is most at home as a writer when describing landscapes, as in his depiction of Homeric Hades by way of the estuary at Huelva in southwestern Spain: “Flakes of white quartzite shine through the water between ribs of rock that veer from red to tangerine to ocher and rust to flame-­colored, flesh-colored, sick and livid.”

As Nicolson relates, Homer, the blind bard of Chios who supposedly composed the “Iliad” and the “Odyssey,” may never have existed. Or, if he did, he most likely wasn’t the sole author of the epic poems for which he became famous. Instead, he may have culled, arranged and interpolated these foundational myths from within a living, oral tradition reaching back — through the Greek Dark Ages — to a primitive, preliterate era of Bronze Age wars and warriors sprawled across the Eurasian plains. “The poems,” Nicolson writes, “were composed by a man standing at the top of a human pyramid. He could not have stood there without the pyramid beneath him, and the pyramid consisted not only of the earlier poets in the tradition but of their audiences too.”