I'm not sure about Piketty per se, but I know that estate taxes are a common trick to break up self sustaining fortunes. The basic theory being that it might be

I'm not sure about Piketty per se, but I know that estate taxes are a common trick to break up self sustaining fortunes. The basic theory being that it might be ok for someone to amass quite a bit of wealth during their lifetime from their own labor, but it's not ok for their progeny to be permanently wealthy because of who their parents happened to be.