The First Wise Traveler to the West - The Wise World Traveler: Becoming a Part of All that You Meet - page 20

As far as is known, there are three major sources of human knowledge: God's revela-
tions, human experience, and human reason. Divine revelation comes as God's message to
humanity. (“And God said, let there be light…”) Experience, also called empirical know-
ledge from the Greek word for experience, teaches us that the sun rises every day in a place
we call the East. And reason is humankind's capacity to move from evidence to inferen-
ce, from premise to conclusion. (To journey east, walk in the morning toward the sun.) We
can move from premise to conclusion by following well-tried rules of reasoning: chiefly,
induction and deduction and a combination of both. And we are guided in reasoning by re-
membering notable and useful empirical conclusions. (Isaac Newton's third law: for every
action there is an opposite and equal reaction; Alexander Hamilton's observations on the
short-lived republics of the Italian Renaissance.)
Throughout the Middle Ages the most important sources of knowledge were said to be
reason and revelation, with reason second to revelation. But following October 12, 1492,
experience came gradually to assume greater and greater importance. There was nothing in
the Bible about geographic worlds yet to be discovered. Nor did Aristotle, one of the most
revered ancient philosophers, suggest the existence of lands far beyond the horizon of the
western sea. And yet, they were undeniably there. Modern science builds on experience,
on careful observation (ideally made several times and shared with others) combined with
reasoning. Experience opens the gates of scientific truth, and October 12, 1492, thus stands
as a milestone in the great journey of modern science.
WHAT IS THE GREAT COLUMBIAN EXCHANGE?
Thomas Jefferson once remarked that there is no greater gift to mankind than the discovery
of a new food. Consider, then, the New World's gifts of food. For more than 10,000 years
the Native Americans of the Andes have been cultivating a root that we know as the potato.
Remarkably adaptive, the potato grows at different elevations and in an astonishing vari-
ety of climates, from temperate to subtropical, from an altitude of 13,000 feet to sea level.
It grows in varied soils, from rich loam to stony clay. Unlike most of the staples known
to Europeans and Asians before 1492, potato seeds and cuttings can be pushed into the
ground with nothing more than a stick—no need for plow and turning board and no need
for draft animals or humans to pull the plow. More remarkable still, the potato does not
need harvesting within a few critical days at maturity. It can be kept in the soil for consid-
erable time after maturing and pulled from the ground, one or two potatoes at a time. For
cooking, potatoes need no pots or fireplaces; a simple fire will do, a considerable gift for
peasants in hovels. It also has high nutritional value, containing vitamin C and numerous
minerals necessary for health. Parts not eaten, such as the peelings, can nourish pigs, the
animal companions of people who live at the very margins of nutritional existence.