The Philosopher's Zone covered the subject of Truth recently, and makes interesting comparison with Nova Magazine's recent treatment of the same subject.
The program starts out by trying to define truth (making the observation along the way that some think that a philosopher who isn't interested in truth is like a doctor who isn't interested in health - note: 'doctor', not 'homeopath', since the simile wouldn't hold in the latter case).
The Correspondence Theory of Truth (derived from Aristotle) is introduced first:
It tells you that a statement is true if it corresponds with the facts.
For example: "grass is green" is true if, and only if, grass is green. The problem with this is that it's really only saying grass is green if grass is green (something is true if it's true) which is a little pointless. The Coherence Theory, on the other hand, states
a proposition is true insofar as it can be fitted into a coherent, consistent body of other propositions.
These theories are not mutually exclusive though, but can be seen as complementary.
Interestingly, the program points out that if you doubt whether we can arrive at the truth (like the newage brigade) then you are a skeptic (in the pure sense of the word of course). So this seems to mean that all alternatistas are skeptics, and skeptics believe in woo. Frightening stuff.
The Social Constructivist Theory of Science has evolved from these theories of truth, peppered by postmodernism, where nothing is objective and any theory is as good as any other theory. This is the form of 'truth' that is popular with alternatistas and believers in all sorts of fictional constructs (like vibrational energy medicine, for example). The commentator on this attack on science states:
The basic point is that it's a kind of a relativism and a skepticism which suggests that you can't pretend that some theories have intellectual merits over others. That's what it comes down to and I think it's a very destructive, pernicious business. [...] The Social Constructivists took off from [Thomas] Kuhn's work and went beyond it to a ludicrous degree where they, for their part, want to deny there's a rational, cognitive intellectual element.
Teaching, as a result is seen as propaganda only, and a pointless exercise since any one theory is just as good as another (EoR won't mention Unintelligent Design, since that doesn't even qualify as a theory). Such an approach is described as both intellectually offensive and dangerous, or
Affirmative action for bullshit.
As the program points out, if all theories are equally good (ESP and astrology get mentioned specifically, but the remit is far larger) then that way lies madness. If everyone's beliefs are equally valid, how can anyone set themselves up as a teacher? Socrates is mentioned: his argument goes along the following lines. If everyone's beliefs are true, and most people (almost universally) believe that relativism is false, then the relativists must concede that their doctrine is false. Hence it refutes itself. Or at least disappears up its own fundament in some form of Möbius loop.
The two forms of skepticism bequethed to us by the Greeks are described: that nothing can be known for certain; and that, since that last statement can't be known for certain, you can only remain in a state of doubt. As the commentator points out, there were many schools of skepticism in Greece, and it may just be that we don't know for certain that nothing can be known for certain. Thus it would seem that the alternatistas are the true skeptical heirs. Of course, EoR doesn't think anyone could really live their lives as fundamentalist skeptics of such an ilk, since they would have to believe some things. Is this food okay to eat? Should I cross the road now or will that truck hit me? A skeptic who believes that nothing is certain and nothing can be known would be standing eternally at the roadside, finding it impossible to make a decision whether to cross or not.
Michel Foucault's approach to truth (that there are no facts, only interpretations) is introduced. By this interpretation, science functions by assessing what works in the physical world.
Nietzsche, on the other hand, is much more extreme, arguing that all truths are individual, and that the truth arises from the struggle for power. EoR wonders how the readers of Nova would feel knowing that their approach to truth seems to most closely parallel the creator of the übermensch?
Of course, maybe nothing said in the program is true.
The whole program is half an hour, and available to listen online or for download.