The social purpose of labeling a scientific statement as true is to differentiate statements that are useful in making accurate predictions from those that are not useful for making predictions

I may be exposing my ignorance here, but I don't understand what you mean by a "social purpose". The purpose you describe sounds like an entirely pragmatic purpose to me; i.e., it's the one that makes sense if you want to discover more about the world -- but perhaps this is also what you meant ?

I wrote this earlier, which is a slightly more detailed version of the same point

I read that comment, and I disagree with its premise: "It's like Aristotle [and Newton] wasn't looking at the same reality". Both Newton and Aristotle (ok, Aristotle not as much) explain not only their conclusions, but the evidence and reasoning they used to arrive at these conclusions, and it's rather obvious why they made the mistakes they made... it's because they were, in fact, looking at the same reality we now inhabit. You'd make the same mistakes too, today, if you knew nothing of modern science but tried to figure out how the world worked.

Furthermore, Newton wasn't even all that terribly wrong (again, Aristotle was a ways off). If I want to predict the orbit of our Moon with a reasonable degree of certainty, or if I simply want to lob a rock across the top of an enemy fortress's walls with my trebuchet, I don't need relativity.

If different scientists are looking at a different reality, how on earth did we keep making better predictions? Thus the appeal to the regularity of phenomena, which rescues the concept of scientific progress...

You make it sound as though the "regularity of phenomena" is some kind of a trick that people invented so they could keep getting tenure, or something. I, on the other hand, would claim that it's simply the most parsimonious assumption, given our observations.

I think that's pretty clearly the case, yes.

Edited to add: On reflection, I think this is not at all clear. Surely some science funding is so directly motivated, but a lot seems to be more related to signaling.

I suspect many Less Wrong readers will Agree Denotatively But Object Connotatively to your statements. As Nornagest points out, what you wrote is mostly true with one important caveat (the fact that we are irrational in regular and predictable ways). However, your statements are connotatively troubling because phrases like these are sometimes used to defend and/or signal affiliation with the kind of subjectivism that we strongly dislike.

I'd agree that a lot of our perceptual reality is self-generated -- as a glance through this site or the cog-sci or psychology literature will tell you, our thinking is riddled with biases, shaky interpolations, false memories, and various other deviations from an ideal model of the world. But by the same token there are substantial regularities in those deviations; as a matter of fact, working back from those tendencies to find the underlying cognitive principles behind them is a decent summary of what heuristics-and-biases research is all about. So I'd disagree that our perceptual worlds are unpredictable: people's minds differ, but it's possible to model both individual minds and minds-in-general pretty well.

As to your second clause, most humans do have substantial social needs, but their extent and nature differs quite a bit between individuals, as a function of culture, context, and personality. This too exhibits regularities.

Humans are symbolic creatures: Meaning that to some extent we exist in self-created realities that do not follow a predictable or always logical order.

I don't understand. Much of our self-identity is symbolic and imaginary. By self-created reality do you mean that our local reality is heavily influenced by us? That our beliefs filter our experiences somewhat? Or that we literally create our own reality? If it's the last one, the standard response is this: There is a process that generates predictions and a process that generates experiences, they don't always match up, so we call the former "beliefs" and the latter "reality". See the map and territory sequence. If that's not what you mean (I hope it is not), make your point.

Humans are social creatures meaning that not only is human survival is completely dependent on the ability to maintain coexistence with other people, but individual happiness and identity is dependent on social networks

yes

Humans are symbolic creatures: Meaning that to some extent we exist in self-created realities that do not follow a predictable or always logical order.

While our internal models of reality are not always "logical", I would argue that they are quite predictable (though not perfectly so). Just to make up a random example, I can confidently predict that the number of humans on Earth who believe that the sky is purple with green polka dots is vanishingly small (if not zero).

not only is human survival is completely dependent on the ability to maintain coexistence with other people, but individual happiness and identity is dependent on social networks.

Agreed, but I would argue that there are other factors on which human survival and happiness depend, and that these factors are at least as important as "the ability to maintain coexistence with other people".