What is an 'idea'? A philosophical puzzle?

I've just returned from giving a talk and working on an evolutionary simulation computer program that I've developed with Brian Lambert here and colleagues in Helsinki, a very nice place with very good colleagues. Now back, I note that the episode of the BBC program In Our Time that was aired while I was away was about the philosopher Bishop Berkeley (1685-1753).  Berkeley was famous in the history of philosophy for many things, but largely for 'immaterialism', the idea that objects only exist in the mind. This might be similar to the classical Solipsists in ancient Greece, who said that all we can actually know are our own thoughts.  The external world need not exist.  Other philosophers pursued similar ideas about perception and reality.  Kant, for instance, wrote about the connection between what our senses can see and the actual reality of the seen (but I confess that this is too burdened with obscure terms for my meager understanding).

Berkeley: if we didn't actually see him, did he exist?

What I found interesting was a quip by one of the guests (Peter Millican, as reported by the moderator on his newsletter after the program), who raised the question: "How would you describe an 'idea'?" Is it really an 'it'?  If so what 'is' it?

Ideas in science
In science we fancy that we are all about the empirical world.  If we are solipsists or Berkeleyites then it may not matter; we either solve the major questions in science in our heads, or not, but it's all up to us since the stuff may not exist outside of ourselves anyway.  Under those rather self-centered conditions, only an inferiority complex would prevent each of us from concocting many Nobel-deserving 'true' stories about the Nature we envision--what could stop us?

Normally, we tend to agree that there is a real world and that we have sense organs and thought organs to perceive some aspects of it and to articulate some generalizations about it--generalizations that may be approximate, but are at least somewhat true of the really-is-true world.

In this sense, an idea is a structured set of relationships between a list of defined concepts of objects.  It need not be rigorous, in the sense that my real ideas may not be anything I can describe accurately to you to the point that you then have the same idea, and vice versa.  But in science we can take these imperfect descriptions or suggestions about reality, and see if our means of perception suggests that they correspond to the reality or not.

These abilities have incredibly impressive power and a phenomenal record of success, I think.  We have extended our natural senses to build equipment and use reasoning (mathematics) to detect and understand things that we believe are real and yet vastly beyond our sensory organs.  Microscopes and telescopes and computers are examples.  The record of ideas and their generalization shows that much about Nature can be organized, and unobserved things predicted with reasonable accuracy, that the reality of reality really is not confined within our own heads.  It's out there!

Models of reality: are they real?  The case of cosmic 'inflation'
As impressive an example of this power is the detection of gravity waves in the cosmic microwave background (CMB) that was announced last week.  Using very high-tech telescopic techniques (measuring 'light' not detectable by the opsin proteins in our eyes, and computer technology far beyond what our brains can manage), evidence was found for a predicted pattern in the CMB.

This pattern is interpreted as showing that very early in the history of the universe, 'spacetime' (the relationships among everything that exists) expanded very rapidly in some parts of the very brand-new universe.  This created some irregularities and they, in turn, allowed gravity and energy to form local concentrations--galaxies, stars, planets, you and me) that purportedly could not occur otherwise.  An alternative theory had been that the universe expanded and contracted endlessly, and in this theory concentrations of matter and energy were possible.

I am no physicist so this post is not about the specifics--plenty of specialists and pop-sci writers will do their best to explain it to you (and me).  E.g., Sean Carroll does a nice job here. But even conceptually, this is so very strange and exotic that one both accepts and questions it at the same time.  We question it for two reasons.  First, and foremost, because for  most of us the whole discussion of early cosmology is totally foreign to common sense.  Secondly, there are some physicists who question whether the data and methods used really show what is claimed.  The analysis is very far removed from normal human cognitive talents, so that interpretation at the deepest level is required to come up with the conclusion.

The usual hype is already out there by the physicists involved and the news media, but this really will be an important finding--not a 'discovery' since the 'idea' is decades old and in a sense is what led to the search--if additional work confirms the interpretation.  Be that as it may, whatever an 'idea' 'is', ones like this are so abstract and yet successful that there should be no questioning of the existence of ideas and their importance.

Non-sensical 'ideas' about reality
The ability to have sensible ideas carries with it the ability to have non-sensible ideas.  We observe the reality in the world (even if imperfectly since our sensory organs are limited), but our minds are constructed to encapsulate these observations and label them and so on.  This means we can give labels to things we just make up in our minds.

The same goes for logic and reasoning.  We in the western tradition, at least, have some ideas about how one is allowed to go legitimately from one proposition about ideas and objects to another.  Something cannot be true and false at the same time, or exist and not-exist, for example.  If we refer to such ideas, they are philosophical or fanciful.

So, even after millennia of philosophical and scientific thought, just in the west alone, it is surprising that CNN saw fit to publish an op-ed piece arguing that the finding of cosmic inflation is proof of the existence of God.  The argument, so far as I could follow its rather vapid content, is that if the universe had a beginning, it had to have an external entity to bring it about--an external cause, as it were, which is God.  Well, CNN is perhaps debatably about actual news, but this is a set of 'ideas' that have no empirical necessity and hence are different from the idea of a 'dog' or 'table', or 'cosmos', for that matter.  The 'idea' of God is more comparable to that of Santa Claus than that of a galaxy, since the latter has empirical relevance and testability.  Santa Claus is an imaginary idea, by contrast.

This has more holes than Swiss cheese.  First, the big bang idea of an origin of the universe is not a new idea at all, nor does inflation suddenly prove such a thing.  Even an infinitely cycling cosmos could, by the same argument, have required an external cause.

But the wishful-thinking of that sort is not the worst aspect in my view.  The fact, if true, that the cosmos began with a Big Bang out of nothing does not imply an external cause.  It only does so based on the daily-experience set of human ideas, that what we see happening has causes of a sort we know about.  We are so frail, relative to the complexity of Nature, that our inability to imagine an effect without a standard cause is no evidence at all that there must be such a cause.  Much of quantum mechanics, for example, violates commonsense and can only be taken as meaningful because of our ability to do experiments and mathematics and so on, that can deal with things beyond commonsense.

Tree fallen in forest; Wikipedia

Worse, however, is the implication that even if there did need to be an external cause of the cosmos, that external cause was God.  That is, was the same 'cause' that (getting really petty relative to causing cosmic inflation!) made Noah build a wooden boat to survive a big rainstorm, or cared whether Abraham sacrificed his son, or wanted some human to live in a gilded palace in Italy while other immortal souls couldn't eat.  You get the idea!

The logic is simply fallacious.  The fact that an external cause were needed, if it were a fact, does not in any way imply that that cause was what we poor humans imagine.  This perverts various 'ideas', ranging from empirical to imaginary, weaves them together into a grander idea that is without serious empirical basis, and claims that the latter has the force of universal laws (of logic).  The Times must be seeking sales to religious believers to have published such an op-ed.

So, what is an 'idea'?  In a somewhat circular way, it is an idea worth thinking about for fun.  But we should not get carried away with its philosophical potential.  We don't really understand much of the physical world, and less of what 'spiritual' even means (if it is 'physical' in any sense).  But we do understand a lot.  We understand enough to know that, all philosophical textbook chapters aside, when a tree falls in the forest, it really does make a Thump! whether or not you're there to hear it.  The cosmic inflation evidence may or may not stand further scrutiny.  But it is an example that shows that we know that ideas can go beyond simple manifestations of the input to our eyes, ears, and nose.  And, speaking of creation, we know that not all ideas are created equal.