This book is one of the better things I have read about the financial crisis. It's a nicely-written and clearly argued case against the efficent markets hypothesis (EMH) and the argument that left to their own financial markets will tend towards equilibrium. In fact a large part of the author's motivation for writing the book seems to be to drive a stake through the heart of the efficent markets hypothesis, which he sees as fundamentally wrong (no argument here!).
As such the book is broadly pro-Keynes, and very pro-Minsky. It takes as a given Minsky's view that markets are inherently unstable and will inevitably swing between boom and bust, and that the busts can be very bad indeed if no action is taken. The suggestion is that Minksy's financial instability hypothesis should replace the EMH as our bedrock understanding of how financial markets work.
Notably this leads him query what central banks are trying to do. He is particularly scathing of Fed, which he suggests tries to combine a belief in the EMH with intervention, when logically they should preclude each other. He argues central banks should refocus their attention on credit expansion and asset price bubbles, rather than consumer price inflation. Notably he therefore believes that bubbles both exist (this might seem obvious, but it's actually an important point) and that central banks can do something about them, though in practice it's credit creation that he thinks should be monitored.
That's the headline argument, but there are lots of nicely structured points building up to it along the way. There's a great section on why even 'fundamental' company analysis on its own can fail to spot the distorting effects of bubbles.
Anyway, definely worth a read, and given that it's both very clearly-written and one of these double-spaced books you can get through it in no time.