Our labor today can be divided into two parts, one part is the labor paid to obtain the means of living necessary for today's survival; the other is the labor paid in advance for future development. When the ratio of the former is greater than the latter, It shows that our labor is still at a lower level; and when the latter is much larger than the former, it shows that our labor level has been greatly improved. 
only through social development, progress, and improving people's efficiency and level can we truly achieve The complete liberation of mankind itself.
The improvement of labor level is an important sign of the development of human society.