There is a theory that there were only two people and thousand people in Joseon.

 A history professor even published a thesis on the theory that there were only two people and thousand people in the Joseon Dynasty. From this, it can be seen that it has its own validity. Although other historians said no, isn't it worth a look? Until now, I understand that Joseon was a society where the distinction between classmates was strict and the professional return of private farmers and merchants was also considered. But it's not. There were only two classes, Yang and Cheon. Think about it. Toegye Yi Hwang and Yulgok Yi I passed the state exam in the past to avoid military service. If you reverse this, even if a family member who was a nobleman among their ancestors had to serve in the military as long as they were both men, wouldn't it mean that they were obligated to serve in the military? Joseon was a system in which all two people were obligated to serve in the military, but Yangban and Seowon were excluded. Both men had to serve in the military unless they were rich enough to enter the Confucian academy and rich family, or if they were not a nobleman who passed the state exam in the past. If you have the same obligation, you can see it as the same class. Looking at the records, there are cases in which a family that produces a lot of officials (forgot their names) dealing with adversity or mathematics has produced aristocrats. Considering the Joseon system, which was not managed by passing the state examination in the past (chronically, the number of state-run students in the past was more than the number of government posts), the difference between Yangban and Jungin was not strictly legal social status difference was a lot of connections. Even a nobleman could farm as a job. Of course, there were many cases of using servants, but I was not told that I was not a nobleman even if I farmed myself. In fact, I think it would have been the difference in property and the power of the family that divided the yangban, middle class, and Sangmin (the three of them). To see the past, you need to buy numerous books, to memorize them, you need a lonely place to study, and you need travel expenses to go up to Seoul. In addition, Joseon's past tests include not only reading scriptures, but also refuting the current national situation, so it is necessary to study not only writing skills but also broad knowledge. That's why it costs a lot of money to take the past test. In addition, if you pass the past exam, there are so many past students than the number of government posts, so if you don't have any connections, you can know many people from a long time ago (in this case, you can be clean) or you have a lot of money to buy them with money.