“This book aims to learn from that mistake. One of its goals is to ask whether Minsky’s demand for a theory that generates the possibility of great depressions is reasonable and, if so, how economists should respond. I believe it is quite reasonable. Many mainstream economists react by arguing that crises are impossible to forecast: if they were not, they would either already have happened or been forestalled by rational agents. That is certainly a satisfying doctrine, since few mainstream economists foresaw the crisis, or even the possibility of one. For the dominant school of neoclassical economics, depressions are a result of some external (or, as economists say, ‘exogenous’) shock, not of forces generated within the system.”