Jeremy Grantham's quarterly investment letter:
"Capitalism has gone through a Darwinistic series of trails and errors, which still continues. For the time being, capitalism has tuned itself to rapid growth at almost any cost. Circumstances such as the hydrocarbon revolution and the ensuing population explosion have allowed for both high growth and high profit margins to sustain the growth. Sustained high margins have in turn trained capitalists--or corporate executives if you prefer--to set high hurdles for all investments....
"Of all the technical weakness in capitalism, though, probably the most immediately dangerous is its absolute inability to process the finiteness of resources and the mathematical impossibility of maintaining rapid growth in physical output. You can have steady increases in the quality of goods and services and, I hope, the quality of life, but you can't have sustainable growth in physical output. You can have 'growth'--for now--or you can have 'sustainable' forever, but not both. This is a message brought to you by the laws of compound interest and the laws of nature."
Complete commentary here.