Is it "ideas OR economics", or "ideas AND economics"?

Max, our 110-pound puppy, was restless. I let him out.

I turned around and there was Lexi (our canine "middle child") giving me a look that said Hey I want to go out too! But Lexi doesn't want to go out by herself. She wants me to go with her. She talked me into it.

And then there's Mish, our oldest. I asked her: Do you want to go out? She looked me straight in the eye and licked her lips. In our house that's universal language for "I want a treat!"

So I told her: You can go out, or you can stay in and have a treat. She wanted the treat. She got her treat, and I went out with Lexi. 

But as soon as I closed the door, I heard the bark that said "Now I'm ready to go out." 

Treats and out, that was Mish's plan.

They're so human in so many ways, our dogs.

 
In Ancient Economic Thought (PDF), in the Alan Samuel essay "Assumptions, Economics, and the Origins of Europe", at one point Samuel struggles to choose between"ideas" and "economics". Let me start at the beginning of his third paragraph:

I may, therefore, risk running against the tide if I treat this discussion in terms of the categories of Pirenne’s arguments ...

Pirenne was a historian; Alan Samuel suggests that Pirenne's views have been superseded by more recent work. (I wouldn't know. But in a PDF on Robert Lucas from Econ Journal Watch, Lucas is quoted as saying he was influenced by "Henri Pirenne, the Belgian historian, who stressed economic forces". This stress on the importance of economic forces could be the most important thing Robert Lucas ever said.) Resume Alan Samuel:

... if I treat this discussion in terms of the categories of Pirenne’s arguments, and if I focus on the question in the terms Pirenne saw it: what was the phenomenon which made life in Western Europe different after the Roman patterns were no longer in effect? However evolutionary the change may have been, and however much one may prefer to see a multiplicity of factors at work, in the history of that period, as of all periods, there was something qualitatively different from life in the former Roman Gaul—different both from earlier times and from the contemporary Roman and Islamic East.

Pirenne was looking for "the phenomenon" -- the one phenomenon that caused Western Europe to evolve in the way it did. Alan Samuel:

It is that difference, and its causation, which still can bear discussion, it seems to me.

Samuel continues then, taking "ideas" as one phenomenon, "the economy" as another: ^[1]

It is true that ideas were fundamental to the changes that took place, but many of those ideas can be traced in the economy... “Ideas or economics” does not, therefore, seem to me to be a very suitable set of alternatives and exclusions, while even “ideas and economics” draws too sharp a line between concepts and their results, which may, in fact, feed upon one another.

He rejects both: "OR" presents us with "alternatives and exclusions". "AND" gives rise to false distinctions between "concepts and their results". Samuel finds big meaning in those little words.

He struggles to choose between "ideas OR economics" and "ideas AND economics", but finds neither alternative acceptable. Finishing the thought, he writes:

The strategies adopted by the leaders of society during the difficult years 400 to 800 were dictated to a significant extent by the underlying ideas about society and its material needs ...

"Society and its material needs" IS the economy. Alan Samuel is saying it was ideas about the economy that dictated the strategies of those difficult years. I have to say he is exactly right. I have been saying that the economy drives civilization up to the peak and down to the trough. Now I have to adopt Alan Samuel's view and say the economy drives civilization even during the trough. In all its phases, the cycle of civilization is an economic cycle.

Economics is ideas about the economy. Ideas and economics don't disentangle.

Should it be "ideas OR economics" or "ideas AND economics"? With Samuel, I reject the question. I cannot choose between economics and ideas. Economics *IS* ideas. At the end of The General Theory of Employment, Interest and Money, after inventing macroeconomics and showing a path out of the Great Depression, John Maynard Keynes asked 

"Is the fulfilment of these ideas a visionary hope?" 

Ideas. His word. He pondered the chance of success for his ideas. He was optimistic:

"I am sure that the power of vested interests is vastly exaggerated compared with the gradual encroachment of ideas."

Economics is ideas:

"the ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Indeed the world is ruled by little else."

The ideas that drive the advance of civilization, those that bring its decline, even those in effect at the bottom of the cycle of civilization, are economic ideas. "Indeed the world is ruled by little else."