If you have ever spent an afternoon with a four-year-old, you know that the most exhausting word in the English language is “Why?”

Why is the sky blue? Why do snakes have no legs? Why do we speak English but our neighbors speak Spanish? Human beings are hardwired to look for reasons. When we see something in our present reality—a strange rock formation, a bitter political rivalry, or a bizarre cultural custom—we desperately want a story to explain where it came from.

In the ancient Near East, scribes answered these questions by writing an etiology.

Derived from the Greek word aition (meaning “cause” or “reason”), an etiology is essentially a retroactive origin story. It is a narrative designed to explain the cause of a present reality. When we read the Hebrew Bible from a historical-critical perspective, we realize that for many of its most famous stories, the reality existed first, and the story was written later to explain it.

By learning to spot these ancient “just-so” stories, we can fundamentally change how we read the text, moving past literalism to uncover the brilliant, profound ways ancient people made sense of their world.

The Geological Etiology: A Pillar of Salt

One of the clearest examples of a biblical etiology is found in Genesis 19: the story of Lot’s wife.

According to the narrative, God is raining down fire and sulfur on the wicked cities of Sodom and Gomorrah. Lot and his family are fleeing, and they are given a strict command: do not look back. But Lot’s wife disobeys, turns her head to watch the destruction, and is instantly turned into a pillar of salt.

To a biblical literalist, this is a terrifying historical event. But to a historian, it is a brilliant geological etiology.

The southern edge of the Dead Sea is one of the most bizarre geological landscapes on earth. It is an incredibly arid, hyper-saline environment where massive halite (rock salt) formations naturally erode into strange, jagged pillars. To ancient Israelite merchants traveling through this desolate, lifeless region, these towering salt columns would have looked remarkably like human figures standing frozen in the wasteland.

The ancient Israelites looked at a naturally occurring, human-shaped salt pillar and asked, “Why is that there?” The scribes provided an etiology: it is not just a rock; it is a woman who disobeyed God and was frozen forever as a monument to her sin.

The Linguistic Etiology: The Tower of Babel

Etiologies were not just used to explain rocks; they were used to explain the complexity of human culture.

In Genesis 11, the Bible addresses a massive anthropological question: Why are there so many different languages? The scribal answer is the Tower of Babel. The story claims that all of humanity once spoke a single language and gathered to build a massive tower to the heavens. God, threatened by their hubris, scrambles their languages so they cannot understand each other, and scatters them across the earth.

This story is a masterclass in ancient political and linguistic etiology, aimed directly at the Babylonian Empire.

When the ancient Judeans were exiled to Babylon, they saw the massive, towering ziggurats (stepped pyramids) that dominated the Mesopotamian skyline, such as the famous Etemenanki. Furthermore, Babylon was a cosmopolitan imperial capital packed with captive peoples speaking dozens of different languages.

To explain this overwhelming, multi-lingual empire and its giant, unfinished temples, the biblical authors wrote an etiology using a brilliant Hebrew pun. The Akkadian name for the city was Babili (meaning “Gate of the God”). But the Hebrew authors deliberately linked it to the Hebrew verb balal, which means “to confuse or scramble.” The story retroactively explains why the world is fractured, while simultaneously mocking the monumental architecture of their captors.

The Geopolitical Etiology: Twins in the Womb

Perhaps the most powerful use of etiology in the Bible is political.

Throughout the Iron Age, the Kingdom of Israel and the neighboring Kingdom of Edom (located to the southeast) despised each other. They fought bitter border wars, raided each other’s territories, and competed for regional dominance. They were closely related Semitic peoples, yet they were locked in perpetual enmity.

Ancient Israelites naturally asked: “Why do we hate the Edomites so much?”

The Book of Genesis answers this question by creating an ethnographic etiology involving two brothers: Jacob (who is later renamed Israel) and Esau (the father of the Edomites). The text claims that the geopolitical rivalry of the 9th and 8th centuries BCE was actually born centuries earlier in the womb of their mother, Rebekah.

Genesis 25 says the twin babies violently jostled each other in the womb. Esau was born first, but Jacob came out grasping his brother’s heel, eventually tricking him out of his birthright. By retrojecting a modern national conflict onto two ancient ancestral brothers, the biblical scribes provided a theological justification for the present political reality: We fight the Edomites today because our founding fathers fought in the womb.

Reading History Backwards

When we treat the Bible as a flawless modern history textbook, etiologies become a stumbling block. We are forced to believe in magical salt transmutations and that every language on earth was instantly created at the base of a single tower.

But when we strip away the domestication and recognize etiologies for what they are, the text becomes profoundly human. The ancient scribes were not trying to deceive anyone. They were simply doing what ancient historians did: they looked at the messy, confusing reality of their world—the weird rocks, the foreign languages, the bitter wars—and they wrote stories to ensure that everything had a divine purpose and a meaningful origin. By understanding etiology, we stop asking if the story actually happened, and start asking why the story had to be told.