Peer review is just a slightly more formal kind of debate, but debate doesn't work and isn't about finding truth.
Traditional empirical science depends on a mechanistic (as opposed to humanistic) principle for obtaining truth: the scientific method.
The traditional scientific method provides a strong principle for evaluating theories. For some fields of inquiry (physics, chemistry), this principle works very well. But modern scientists want theories about economics, nutrition, medicine, climate change, computer vision, and so on. The traditional method does not justify theories in these fields.
To go further, we must discover new mechanistic principles of truth-seeking. We should never ask: "What would it be good to know?" That road leads to alchemy. Rather we should ask: "For what types of questions can the answers be evaluated by mechanistic principles?"
What is the "scientific method" and can you point to an important scientific discovery made in history that used this method and only this method? Of course, I am asking for an actual historical event, not a rational reconstruction of a historical event.
Obviously, my question is rhetorical and is meant to point out that any such method is far from "mechanistic".
[This is a version of an first draft essay I wrote for my blog. I intend to write another version, but it is going to take some time to research, and I want to get this out where I can start getting some feedback and sources for further research.]
The responses to the recent leaking of the CRU's information and emails, has led me to a changed understanding of science and how it is viewed by various people, especially people who claim to be scientists. Among people who actually do or consume science there seem to be two broad views - what they "believe" about science, rather than what they normally "say" about science when asked.
The classical view, what I have begun thinking of as the idealistic view, is science as the search for reliable knowledge. This is the version most scientists (and many non-scientists) espouse when asked, but increasingly many scientists actually hold another view when their beliefs are evaluated by their actions.
This is the signaling and control view of science. This is the "social network" view that has been developed by many sociologists of science.
For an extended example of the two views in conflict, see this recent thread of 369 comments Facts to fit the theory? Actually, no facts at all! . PhysicistDave is the best exemplar of the idealistic view, with pete and several others having extreme signaling and control viewpoints.
I wonder how much of the fact that there hasn't been any fundamental breakthroughs in the last fifty years has to do with the effective takeover of science by academics and government - that is by the signaling and control view. Maybe we have too many "accredited" scientists and they are too beholden to government, and to a lesser extent other grant-making organizations - and they have crowded out or controlled real, idealistic science.
This can also explain the conflict between those who extol peer review, despite its many flaws, and downplay open source science. They are controlling view scientists protecting their turf and power and prerogatives. Anyone thinking about the ideals of science, the classical view of science, immediately realizes that open sourcing the arguments and data will meet the ends of extending knowledge much better than peer review, now that it is possible. Peer review was a stop gap means of getting a quick review of a paper that was necessary when the costs of distributing information was high, but it is now obsolescent at best.
Instead the senior scientists and journal editors are protecting their power by protecting peer review.
Bureaucrats, and especially teachers, will tend strongly toward the signaling and control view.
Economics and other social "sciences" will tend toward signaling and control view - for examples see Robin Hanson's and Tyler Cowen's take on the CRU leak with their claims that this is just how academia really works and pete, who claims a Masters in economics, in the comment thread linked above.
Robin Hanson's It's News on Academia, Not Climate
And Tyler Cowen in The lessons of "Climategate",
Of course, both Hanson and Cowen believe in AGW, so these might just be attempts to avoid facing anything they don't want to look at.
As I discussed earlier, those who continue to advocate the general use of peer review will tend strongly toward the signaling and control view.
Newer scientists will tend more toward the classical, idealistic view; while more mature scientists as they gain stature and power (especially as they enter administration and editing) will turn increasingly signaling and control oriented.