As noted by FT columnist Martin Wolfe

I see three broad lessons.

The first, which was taken forward by Minsky, is that we should not take the pretensions of financiers seriously. “A sound banker, alas, is not one who foresees danger and avoids it, but one who, when he is ruined, is ruined in a conventional way along with his fellows, so that no one can really blame him.” Not for him, then, was the notion of “efficient markets”.

The second lesson is that the economy cannot be analyzed in the same way as an individual business. For an individual company, it makes sense to cut costs. If the world tries to do so, it will merely shrink demand. An individual may not spend all his income. But the world must do so.

The third and most important lesson is that one should not treat the economy as a morality tale. In the 1930s, two opposing ideological visions were on offer: the Austrian; and the socialist. The Austrians – Ludwig von Mises and Friedrich von Hayek – argued that a purging of the excesses of the 1920s was required. Socialists argued that socialism needed to replace failed capitalism, outright. These views were grounded in alternative secular religions: the former in the view that individual self-seeking behaviour guaranteed a stable economic order; the latter in the idea that the identical motivation could lead only to exploitation, instability and crisis.

Keynes’s genius – a very English one – was to insist we should approach an economic system not as a morality play but as a technical challenge. He wished to preserve as much liberty as possible, while recognising that the minimum state was unacceptable to a democratic society with an urbanised economy. He wished to preserve a market economy, without believing that laisser faire makes everything for the best in the best of all possible worlds.

(emphasis mine)

In fact, this may be the best message to economics professors out there: that reality matters more than your philosophy.