When it comes to economics, it's easy to get caught up in big ideas: Money, the markets, trade, labor and more.
Now, believe it or not, the study of these ideas can all be traced back to one guy in ancient Greece — a mercenary who lay down his weapons, thought long and hard about household management and then wrote a text about it.
So let's take a look backward to where the original idea of economics came from and why that's important today.
1. Xenophon, the mercenary turned armchair philosopher