"The book's central thesis is that when the rate of return on capital (r) is greater than the rate of economic growth (g) over the long term, the result is concentration of wealth, and this unequal distribution of wealth causes social and economic instability. Piketty proposes a global system of progressive wealth taxes to help reduce inequality and avoid the vast majority of wealth coming under the control of a tiny minority." #CapitalInTheTwentyFirstCentury
https://en.m.wikipedia.org/wiki/Capital_in_the_Twenty-First_Century
Doc Freemo 
Up until the point that it incorrectly assumed wealth disparity is the same as instability they lost me. There is no basis for that, it is more accurate to say that the lower the quality of life of the majority of the population gets the worse a society is (and becomes instable)... these two things are **not** the same though they are assumed to be.
