[rtfeldman]

It's actually not sensible to assume that basic principles apply to things that are complex and subtle.

For example, a basic principle for centuries was that metal is too heavy to float, therefore it was clearly too heavy to fly. Simple, basic, and completely wrong - see for example today's airplanes.

This is not to say that the opponents of austerity must have it all figured out, but rather that history has not been kind to ideas of the form "this complex system must surely follow certain common sense principles".

[adolph]

a basic principle for centuries was that metal is too heavy to float, therefore it was clearly too heavy to fly

Do you have any source for this, or are you making it up? For many centuries, the state of the art in metallurgy was not sufficient for making watercraft, much less aircraft. However this did not stop people using the available technology to make such flying things as arrows.

[ctdonath]

I didn't say "common sense principles", I said "basic principles". Most complex systems surely follow certain basic principles.

Apparently "don't spend money you don't have on negative-return investments" isn't common sense.