Why Did Portugal and Spain Explore and Colonize?

We know how the Portuguese and Spanish built two of the vastest, richest empires in history. But having the capability to explore and colonize doesn’t adequately explain why nations do it.

The Chinese for millennia had the means to explore and colonize but seldom did. The Romans’ world centered on the Mediterranean, and they lacked the maritime technology to explore the Atlantic or venture around the Horn of Africa or into the Indian Ocean. But what they lacked in technology they could have invented if the demand for greater maritime exploration then existed. The fact is neither they nor the Chinese felt the need to devote their resources to sea exploration as the Western Europeans did in the 15th and 16th centuries.

The development of space exploration provides insight into the Age of Discovery. Time and resources are scarce, and if given the choice, people would prefer to spend them in safe investments. Man would arguably have never reached the moon without the Cold War, which created the conditions necessary to devote time and resources to the task. In this instance, the threat of mutually-assured destruction spurred the United States to beat the Soviet Union to the moon.

A look at Western Europeans’ motives for venturing beyond their known habitations in the Age of Discovery (ca. 1400–1650) provides a…