Q: What makes any idea a good one?
A: A context in which it's useful.
Let's call this context a body of thought--a collection of previously installed good ideas. Modern dance is a body of thought. The discipline of chemistry is a body of thought. Commercial fishing and the Spanish language are bodies of thought. Good ideas include new nets, new chemical syntheses and new word usages ("niggah").
A body of thought is bit like a biological species: An abstract thing that is mirrored by and exists in embodiments. An individual velociraptor and its fossil femur embody the species we call "velociraptor." An individual chemist and a molecule she draws each embody what we call "chemistry."
Though these bodies are abstractions, still they have structure. Their structure is in the relationships that the component good ideas have to one another--and shows up in such places as in the table of contents of a chemistry text book and in the grammatical categorization of the words of a language.
As good ideas accumulate, previously installed ideas may no longer work well together, and so cease to be good, leading to removal or refashioning. Though the structure of the body of thought evolves, it doesn't evolve arbitrarily, because it survives only if it functions. So let's think of these bodies as boats, to which our culture adds and subtracts, but doesn't change in a way that makes them not seaworthy. Seaworthiness is survival, and it exerts a selective pressure.
Like species and boat designs, bodies of thought may persist or go extinct or evolve or diversify: Natural philosophy begat physics which begat cosmology and particle physics, etc.
But first the bottom line: We don't get new parts for free. Instead the individuals that sustain a body of thought—the ship's crew--pay for each new part. Before money, payment was in admiration, which elevates a creator's status as it accumulates, and this is still the main currency in scholarship, art, politics, teaching, journalism and the evolution of language. It may seem like no one became famous for "niggah," but you weren't there at the creation. It may seem like grade school teachers enjoy little prestige and influence, but you are not a child.
The closer and more pervasive your admirers are, the more admiration you feel. Yet no culture can be more dense on the ground than about one person per square foot, even if the members are two year-olds. So mass appeal brings distant appeal, which brings diminishing returns on admiration and the perception of influence. Financial statements of booming record sales in Japan don't do it like the cheers of fans in a stadium. Add the fact that the global population is finite and you'll see that status too has an upper limit. There's no higher station than King of the World. This means there's only so much prestige to go around.
Not so money, which governments can go on printing forever, at least in principle. With money and patenting, Ms. Widget gets paid to invent even inglorious essentials she never would have invented otherwise. A moneyed society produces more good ideas and makes them faster. Plus it produces stars who never play stadiums and purchasable status symbols such as Rolls Royces (which get how many miles per gallon?).
The new parts to the ships get installed in port, of course--in universities, in record companies, in patent offices, in news rooms. Their inventors usually work close to the hull, though visionaries may take in much more of the ship. The new contributor may make a part that mates precisely with parts already installed or one that lays on top as collage, paint or ornamentation.
Although a part may fail to suit the ship its creator had in mind, crew that's ashore from another ship may notice it and take it for their own ship. So what at first does not look like a good idea may still turn out to be one. But unless a creator has a patent or the other crew is generous, only the finders receive the payment, whether in respect or money.
Now how about we size up the fleet?
The scholarly disciplines are the delicate vessels that never sail out of sight of the academic harbor—though their heartier offspring the applied arts escape. Religions are the battleships and aircraft carriers: Very big, very robust, defenders and menaces of other ships. They sail the high seas in all weather, but they also ply the bays and harbors and even inland waterways. In the real world they ply the minds of the proletariat and aristocrats and merchants alike.
With religion you get to travel the world, meet interesting people, and conquer them. And as in the navy, wearing the uniform may be ample reward for the crewman, lessening your need to earn worldly distinction. You're part of something bigger after all. Belief in an abstract external reference frame enables one to earn self admiration and self respect from undistinguished, internal and/or unwitnessed creations.
In this ship scheme, the sea of course is the minds of the living. The world the sea surrounds is the intellectual sphere. Some forgotten cultures and dead languages still sit on the dry docks of unvisited stacks in the library, although they may no longer be able to float.
Floating is the main thing about bodies of thought, for this is how they move from mind to mind. Note though that only a very small body of thought fits entirely in one mind; and even if it did, it's mirror image may float on the surface of other minds simultaneously. Meanwhile, one individual may comprehend many ships at once, and perhaps serve on several crews. Yet mental space is finite, leading to competition, predation, symbiosis and an ecology of ships.
Oh, why do I think this is even interesting? For one I wanted to build a bigger picture around my idea of an economy in prestige. Also it's that I think an apt metaphor--like Lakoff's parenting and Dawkins's meme--really explains things, and that it guides thought in the way that a theory or model in science prompts tests and applications. Yes, we already know that religions are like viruses and that genes are like ideas. But as I see these metaphors being used, not enough gets made of the fact that genes and ideas have no fixed or absolute value. In truth their value is contextual--their utility or neutrality or disadvantageousness relates to the system in which they appear. Also ideas do not move themselves around, as simple gene analogies seem to overlook, and virus analogies neglect that other things besides viruses carry genes too. And a final viral quibble: Where are the people who aren't hosting the viruses? What are they up to?
I suppose I could have kept the metaphor 100% biological just by labelling the more cuddly bodies of thought "koalas" instead of viruses. Then I could have placed the koalas into an interactive food Web with other bodies of thought, which would be members of other biological species. But what's our own relationship to such a picture? How are we mutating these creatures of thought, and why?
I think we get answers to these question by moving to the sea and demanding payment for parts. Plus boats are simpler than biological species, "floating" and "sailing" are more vivid than "survival" and "reproduction," and anyway what does koala sex have to do with moving ideas around? In case this new mix of metaphor is non-obvious, original and not utterly clunky or uninspiring, I wanted post it. Just remember you read it here first.