The Fourth Part of the World: The Race to the Ends of the Earth and the Epic Story of the Map That Gave America Its Name by Toby Lester

What is the scale of the world? The first recorded answer to this was in the 3^rd century BCE by Eratosthenes, a Alexandrian Greek astronomer/geographer who measured the circumference of the Earth to be 39,375 km (the actual value is 40,075 km-- that's less than 1% error!).

Geography as a discipline, is one which in the post-modern era, has little meaning as compared to ages past. Today, "geography" brings to mind memorizing maps, continents, and locations easily accessible conceptually (and usually, physically) on the well-measured and explored contours of our planet. To a more formal definition, the modern geographer utilizes computer modeling to study the human-environment relationship.

However, in the world of Eratosthenes, Ptolemy, and geographers for more than a millennium, contrasting the known size of our world with how little is known of it sets the study of maps and their intrinsic meaning holds a both philosophical and adventurous call. The map, of course, is the original player's guide for ages past; in the truest sense of what a map should do, the proper cartographical guide should be your itenerary, your travel-log, your translator, and your fortune-teller for the journey not yet begun.

The reader cannot truly appreciate a "story of a map" until one readers the first few chapters of Lester's book. Outright, The Fourth Part of the World is the backstory and tale of the the Waldseemüller map, the centerpiece of a 1507 revision of Ptolemy's Geography, which holds the historical distinction of being the first document which (1) recognizes the New World as a separate continent, and not an eastward extension of Asia and (2) identifies this new landmass as "America" for the first time.

While the map itself has its own beginning and ending (curiously disappearing for nearly 400 years) which brings it to the Library of Congress today, the tale behind the map is a sojourn on the scale of centuries which encompasses Western history from the Fall of Rome to the dawn of the Age of Exploration. Set firmly in the Eurocentric mindset of exploration (the Mongols, Songhai, and Arawaks knew just where they lived, thank you very much), the seeds of cartographic expansion begin with the great conquest of Eurasia in the thirteenth century by Genghis Khan.

When the Mongols hit the geopolitical landscape of the 1200s, they changed everything-- a disciplined military force which could strike like a legion and scatter like bandits. Often, the Mongol Empire is associated with Chinese and Central Asian history, but their effects were (for the time) global. Like dominoes from Japan to Ireland, one kingdom's fall affected all those around them until the percolation of the Khan's influence reached the Vatican.

In grade school, the canonical rationale for the beginning of the Age of Exploration was late Medieval trade with the Middle-East; Lester argues, however, that the primary motivator for the eastern reach of Latin Europe was political-- the Turkish expansion in Anatola in the 11^th and 12^th centuries (which ultimately triggered the Crusades) pressed Greek (Byzantine) Christians too much for Latin Europe's comfort.

While the European conception of the Far East was steeped in mythology and fantasy, they often looked to the East for salvation. The East was the beginning of light and hope, not only a geographic interpretation, but philosophical and religious as well-- theologians of the day saw history as an expansion from east to west, as the sun marches across the sky. The oriens ultima was the Edenic earthly paradise from which the Next Coming, the religious hoped, would arrive to unify the world under their faith. Mythic figures such as Prester John, to save the world to Gog and Magog, to destroy it, inhabited the lands of the silk-worms and long-lived.

Seeking alliance with the growing Empire (a Christian redeemer perhaps?) who seemed to scare the Islamic states threatening Christian Europe, Popes, kings, and adventurers looked to the land of the Great Khan for the future. The mythic figures stopped being those of fantasy, such as Prester John, and began to be flesh-and-blood adventurers such as Marco Polo and Friar William.

Philosophically, the cosmology of the late Medieval era was concise-- the world existed as three major pieces of land (Europa, Africa, Asia) rising out of the watery sphere of the sea. Contrary to what is commonly taught about pre-Columbian thought, it was well-known in Europe since the Classical Era that Earth was in fact a sphere. Jerusalem was the theological and physical center of the world, where the continents essentially met, and the Ptolemaic spheres of the heavens moved above.

As the Latin Europeans sought to fill in the gaps in their three-part world, the Earth as we know it began to unfold for Western culture. Perhaps it is because so much of history post-Columbus is canon in school curriculum, the story of exploration begins to lose a bit of its luster-of-the-unknown when the Genoan Admiral arrives on the scene. Throughout the work, there is a steady progression of storyline from Middle Age philosophers such as Franciscan monks and early Papal emissaries to China to the Portuguese hugging the African coast (enslaving along the way), the lucky wanderers (Christopher Columbus), and shameless self-promoters as Amerigo Vespucci. This narrative weaves an intriguing tapestry of exploration and cultural growth.

Vespucci's journey itself was the Fourth Part which rocked the philosophical grounds of the era. Columbus' "discovery," at its own time, was throught to be a relatively minor success, as many thought that his islands happened to be a second set of Canaries. Sailing to latitudes over 50 degrees south of the equator had put Amerigo's ship at the fabled Antipodes of the Earth, a fourth land to redefine the deep islands of the Atlantic. This expanding world, embraced by the growing humanist movement across Europe exploded the Renaissance, and the first viable attempts in over a thousand years to revive the Roman Empire sprung to life; with this, two German thinkers-- Martin Waldseemuller and Matthias Ringmann-- proposed a new edition of Ptolemy's world-defining work.

A philosophical work about humankind's literal and theological place on Earth, The Fourth Part of the World is a journey of the mind and spirit as much as it was across the sea. Exploration is a sincerely human endeavor, which has always been more than finding a new land beyond your view, but within oneself. Growth of the soul is always more fascinating than growth of the maps. The heroism of economic and social subjection are not to be glorified as the men who were not the explorers, but the quiet students of cosmology who studied and wrote in the libraries, monasteries, and universities back on the Continent. These philosophers (in the truest sense of the word) drew the new bounds and directions of thought for the coming centuries. To pore over a map is to explore within and without.

And, if you're lucky, you get something named after you.