“I want to know what were the steps by which men passed from barbarism to civilization.” — VOLTAIRE.

This quote opens the introduction to the first volume of Will Durant’s The Story of Civilization.

Later, Durant identifies, “three steps that led from the beast to civilization — speech, agriculture, and writing.”

Trade deserves to be in Durant’s list as well. As discussed in my last post, in The Rational Optimist Matt Ridley convincingly argues that trade was one of the most, if not the most, pivotal developments in humanity’s rise. It can be said to be what distinguishes us from all other hominids and animals. It long pre-dates agriculture. In fact, it is what made agriculture possible. As Ridley writes (emphasis added):