Practically speaking, what has relativity done for us? Or plate tectonics, for that matter? We still have catastrophic earthquakes, and we still can't time-warp with wormholes. How long have these theories been around now? Sure, they may be useful down the road, but probably not within the next decade or two. And evolution? Don't get me started on the practical applications of pondering our origins and the immediate tangible rewards thereof.
Theory provides the foundation for scientific disciplines. Einstein's early breakthroughs eventually led to the computing revolution. Plate tectonics is an integral part of geology, and probably helped petroleum companies make plenty of discoveries. Evolution is the basis of biology today, and understanding our ecological impact on the environment would be considerably more difficult without it. Without these ideas, there is practically no understanding of the universe that we live in- we could have all of this data, but it would make no sense.
And speaking of the obesity epidemic, heart disease, and whatnot... How many of these phenomena were caused directly by "scientific breakthroughs"? It could be (and has been) argued that artificial sweeteners, one such breakthrough, have actually contributed significantly to the obesity epidemic. There can be little doubt that our mostly sedentary lifestyles directly contribute to obesity as well as heart disease, and how much do you think we would sit around without our modern technology? And while we may be more aware of the world we live in now, how much of it have we destroyed or defiled with our science? (See also: DDT, plastics, killer bees.)
It is rather difficult to make any kind of coherent argument without knowing considerably more about your topic. Am I to believe that reading books, since one is technically sedentary while reading, contributes to fat accumulation? Particular nutrients (carbohydrates) break down easily into glucose, which drives insulin secretion, which regulates fat accumulation.
Here is Taubes' Berkeley lecture from 2007, hopefully you'll find it edifying:
http://www.youtube.com/watch?v=AVvZP2av5Mk
Don't get me wrong, the quest for knowledge is a noble one. We have learned how to treat many diseases, feed more people, squeeze ever more people onto a planet that can barely support them, and even look for other planets that may be our only hope of continued existence once we've finished this one off. But human beings are ill-prepared to handle the knowledge we seek. We learn how to string hydrocarbons together, and what do we make? Styrofoam! We learn how to launch satellites, and what fills our exosphere? Space junk. We learn how to split atoms, and what's the first thing we make? Yeah.
The misuse of knowledge is a very old problem, and it will not go away by putting our head in the sand. We must become considerably smarter if we're going to use technology safely.
I must admit that I am very confused by your post. Are you trying to say that people do not experience hallucinations?
No, what I'm saying is that every person would go through this transition where they would have auditory/visual hallucinations, and its clear that not everyone at the time, centuries ago, did.
I do not believe that Jaynes' theory implies that exactly. As I understand it, there are particular social conditions that were once widespread that encouraged hallucinatory experiences. I would expect people to still experience hallucinations today, and they do: imaginary childhood "friends", dead relatives, and "god".
but I haven't seen anything that can be used to dismiss it today
I have, see the following;
Block, N. (1981). Review of Julian Jayne's Origins of Consciousness in the Breakdown of the Bicameral Mind. Cognition and Brain Theory
Implying that consciousness is a cultural construct?!
I believe Ned Block's criticism was that culture somehow changed to reflect what humans were doing all along. With what we understand about the role of language in thought, this now looks like nonsense. Broadly speaking, yes, consciousness is a cultural construct, but so is agriculture, and the Internet.
Asaad G, Shapiro B. What about the bicameral mind? Am J Psychiatry 1987
Dennett, Daniel (1986). "Julian Jaynes's Software Archeology". Canadian Psychology
That auditory hallucinations played such a major role in human human mind and history is somewhat difficult to believe.
An audio hallucination sounds just like the real thing to the brain. It can be pretty mysterious if you experience it, and do not know what it is. I do not find it at all difficult to accept that a group of people could adopt a "useful" interpretation of such an experience, such as attributing it to "god" or some other relation. In fact, I've met people who currently have these experiences, and attribute them to "ghosts" or "god" or whatever. It would seem that such talk is readily dismissed as nonsense. I tend to have some respect for the experiences of others, though perhaps not their interpretations.
Though I have been quite a fan of Dennett over the years, I am not familiar with his latest views, if they have in fact changed.
As for the transition from a bicameral world to the one we inhabit today, Jaynes discusses his idea in detail, perhaps you've forgotten it?
Well if your talking about religion, schizophrenia and the general need for external authority in decision-making as being the "left overs" of bicameralism, I would argue schizophrenia is a real chemical imbalance that has nothing to do with religion, but might have more in common with creative genius, http://www.personalityresearch.org/papers/byrd.html
I do not find "a real chemical imbalance" to be very illuminating, even if it does imply a neurotransmitter deficiency. There are a few interesting associations with schizophrenia, but Jaynes proposes a far more useful way of looking at the condition.
And a need for external authority in decision-making, that's not a real strong argument in itself, as there are plenty of other reasons for this from even an evolutionary perspective.
I do not understand this criticism at all, please elaborate.
All life evolves by the differential survival of replicating entities. -- Dawkins