You see the emergence of Neo-Confucianism. But one question is, well, what allowed all of this innovation to take place? And also what allowed for the stability of the Song Dynasty? When you look at it on the timeline like this that's covering over 2,000 years, it might not look that long, but when you actually think about it, this is over 300 years of dynastic rule by one dynasty. Now it is split in the middle between the Northern Song and the Southern Song that happens in 1127, and we'll talk about that in a little bit. But for the most part, it is a very prosperous time for China. The population actually grows from roughly 50 million people during the Tang Dynasty to, it is estimated 100 million people by the Northern Song Dynasty, and eventually keeps growing so that by the time we get to the Ming Dynasty, we have a population of about 200 million people.