I read the coolest little tidbit today in The House of Wisdom. It has to do with the invention of algebra. According to this author (and the source he cites; more on this in a moment), algebra was developed by a man named al-Khwarizmi during the earliest years of Islam. He and other leaders in Baghdad were trying to refine the codes of justice that had been around since before Mohammad’s revelation from Allah. They were especially concerned about inheritance law. Prior to Islamic rule, the standard practice in the various Arabic-speaking clans and tribes in the Near East was similar to medieval European primogeniture: the oldest son of a deceased man inherits everything, and everyone else is at his mercy.

al-Khwarizmi and his associates wanted a statute that was more just and that provided for all members of a deceased man’s family, not just the oldest son. After much discussion, they came up with this: When a man dies, his widow inherits one quarter of his estate. His children then inherit the remaining three-quarters of the estate, with sons receiving twice as much as daughters. This is not especially fair by modern standards, but it beats having to jump on a ship and sail for Australia with a bunch of convicts right because your father died and Ramsay Bolton is your older brother.* Given the gender roles of the time and place, this is a thoughtful statute that considers the well-being and dignity of all members of a family. I’m a fan.

*Please excuse this ridiculous metaphor. This is what happens when I read too many books at once.

There was one problem: no one knew how to figure out the dollar amounts to disburse to each person. The mathematics of the situation would be slightly different in each family, of course, and no one knew how to do math that involved – what are they called? – variables. So al-Khwarizmi went home and invented algebra.

After I read this anecdote in The House of Wisdom, I looked back at the plan for inheritance law that I just summarized above, and I got shivers down my spine. (This whole episode took place on BART. Is there a club for people who have gotten shivers down their spines on BART? If not, there should be.) Because once you’re thinking about algebra, the scenario looks like something straight out of your 8^th grade math textbook. And then I went home and wrote this on a Post-it:

And then gosh, look at the time! I believe I have an appointment with a toothbrush.

In all seriousness, I love that this 7^th-century Muslim leader invented an entirely new field of study out of a desire for a sort of justice that was on some level mathematically impossible in the world he was born into. The cynic in me wanted to fact-check the story because I posted it, because it really does feel too good. But it’s written in a history book with footnotes, and the footnote on the anecdote in question cites Berggren’s Episodes in the Mathematics, so maybe it really is true.