Brad Delong summarizes and links some quotes from dueling Freshwater (Classical Macro) vs. Saltwater (Keynesian and others) at Macro Wars

The conflict in many ways boils down to this: is economics to be philosophy where internal, logical consistency of the theory is most important and absolute faith in the theory is commanded of all true-believers (the Classical / Freshwater view), or is economics to be a science where empirical data about how the world actually works is to rule (Keynesian and others in Saltwater schools)?   In my opinion, the Freshwater/New Classical school with it’s message of  “completely free markets, absolutely no regulation ever, government is always evil, private corporate ownership is hollowed”  is no better than old-style Marxism: it’s philosophy and religion masquerading as a socil science.  If we’re ever going to get somewhere in improving the people’s lot in life, we have to deal in reality, not fantasies of worlds than can never be because we made impossible assumptions.

BTW: my favorite quote is from Robert Solow (saltwater) about why he doesn’t engage the freshwater folks in debates much anymore:

Suppose someone sits down where you are sitting right now and announces to me that he is Napoleon Bonaparte. The last thing I want to do with him is to get involved in a technical discussion of cavalry tactics at the Battle of Austerlitz. If I do that, I’m getting tacitly drawn into the game that he is Napoleon Bonaparte.