Algorithm: From Baghdad to ChatGPT, a Word's Journey

Today the word algorithm sounds like the most modern thing imaginable: it decides which video shows up on your screen, which route your GPS takes, and how ChatGPT answers. But the term was not born in Silicon Valley, nor in any twentieth-century laboratory. It comes from the name of a single person: a mathematician who worked in Baghdad more than twelve hundred years ago. The word that defines our digital age is, in fact, the distorted surname of a medieval scholar.

The man behind the word

His full name was Muhammad ibn Musa al-Khwarizmi (c. 780 – c. 850), and he was one of the great scholars of the Islamic Golden Age. He worked at the House of Wisdom (Bayt al-Hikmah) in Baghdad, the great center of study and translation that the Abbasid caliph al-Ma'mun had turned into the intellectual heart of the world. There, around the year 820, al-Khwarizmi wrote treatises on mathematics, astronomy and geography that would change the history of knowledge.

The curious thing is that «al-Khwarizmi» was not a personal name but a place-name: it means «the one from Khwarazm», the region south of the Aral Sea, in present-day Central Asia, where his family came from. Just as we might say «the Londoner» or «the Roman» today, his contemporaries simply called him «the one from Khwarazm». From that geographical nickname would emerge, centuries later, one of the most used words on the planet.

How a surname became a method

One of al-Khwarizmi's books explained the decimal numbering system he had learned from Indian sources: the numerals we now call «Arabic» and the revolutionary idea of zero as a placeholder. When that work reached Europe and was translated into Latin in the twelfth century, the translator Latinized his name as Algoritmi, and the text circulated with a title that began: Algoritmi de numero Indorum («Algoritmi on the number of the Indians»).

European readers, who did not know that «Algoritmi» was the name of a man, understood something else: they thought the word denoted the method of calculating with Arabic figures. So «algorithm» came to mean the procedure for doing sums with the new system, and little by little, any ordered sequence of steps for solving a problem. A person's name had turned into the name of a technique.

The hidden relatives: cipher and algebra

From that same root came words we still use without suspecting their origin. The medieval Latin algorismus gave English «algorism» and, by way of Old French, the word «cipher» itself wandered alongside it: for centuries, calculating with the new figures was simply «ciphering».

And there is an even more famous relative. Al-Khwarizmi's other great treatise was titled Kitab al-jabr wa al-muqabala, and from the word al-jabr —meaning «restoration» or «reunion of the parts»— we get «algebra» directly. Curiously, in medieval Spain that same term was also used for bones: an algebrista was someone who knew how to «restore» or set dislocated bones. If you enjoy these stories of words with a double life, look also at the origin of «sarcasm» or where «avatar» comes from.

From the House of Wisdom to your phone

For centuries, «algorithm» was a technical word used only by mathematicians. Its great leap came in the twentieth century, when computing pioneers needed a precise term for «a finite list of instructions that solves a problem»: exactly what a machine can execute step by step. From there to artificial intelligence and the systems that decide what is human and what is not was only a short step.

So every time someone complains about «the algorithm» of a social network, they are, in a way, mispronouncing the name of a Persian mathematician who lived in Baghdad when Europe had not yet invented the mechanical clock. Few words have traveled so far: from a Central Asian place-name to the House of Wisdom, from there to the Latin translators of the twelfth century, and from there, a thousand years later, to the most everyday corner of our digital lives.

References

1. «Al-Khwarizmi», Encyclopædia Britannica. britannica.com
2. University of Melbourne, «Why are algorithms called algorithms? A brief history of the Persian polymath you've likely never heard of». findanexpert.unimelb.edu.au
3. «Al-Khwarizmi», Wikipedia. en.wikipedia.org
4. Douglas Harper, Online Etymology Dictionary, s. v. «algorithm». etymonline.com

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Do you enjoy the stories behind words? Continue with the origin of «avatar» or explore the whole etymology series.