What does "theory" actually mean ?

Alternative title : Ten Times Scientists Didn't Use The Word Theory To Mean A Well-Tested Model That's Almost A Fact Because That's Not What The Damn Thing Means So Just Get Over It Already.

Admittedly, I do keep flip-flopping on whether "theory" means, "incredibly well-tested" model or something else. This post should definitively clear that up by making it abundantly clear than everything is much more complicated than that.

Clearly there are some theories which do extraordinarily well - sometimes so well that theory and fact are indistinguishable. It might be fair to start to describe these as laws, not theories - the law of gravity, the law of evolution. Both of these things are established factual processes. Yet even these are like Russian dolls : within them we find detailed theoretical models of how they occur, and within those we find competing hypotheses as to how particular aspects proceed and even rivals to the theory - but not the laws. Gravity is a thing. Evolution happens. It's the mechanisms by which these things occur that's open to debate (at least a little bit), not their very existence.

Even if we were to insist that hypothesis only means, "explanation with little or no testing" (which it does) and theory only means, "well-tested explanation" (which it doesn't), then it wouldn't be easy to distinguish between the two. No strict criteria of what "well tested" means exists. It's probably impossible anyway, given the incredibly diverse nature of theories. You can't equate cat emotions with the distortion of spacetime around a black hole, or at least you shouldn't.

The reality is, though, that the vast majority of theories fall somewhere between these two extremes. They aren't just speculations based on limited data, and they aren't so convincing that no other explanations are plausible. They've had some testing and they generally work, but they have room for improvement. Some of them might turn out to be completely wrong, others just need tweaking.

I'm all for rigorous definitions wherever that's possible and appropriate. But in the case of "theory" I think that neither is the case. The simple truth of the matter is that science isn't always purely objective. It's a murky, messy business of turning facts into models, testing those models, rejecting some while provisionally tolerating others. Pretending that it's more objective than it actually is won't work, because it simply isn't true. Would it be nice if it was ? Sure ! But that's not what it's like, and that murkiness is sometimes what makes it fun.

No definition will stop the most ardent from bullshitting about science, because these people simply do not care - and you can't argue with someone who doesn't care, you can only have shouting matches. But for the rest, let's not set ourselves up for disaster by pretending we know things we do not. Simply admit the plain truth of it - that we know hardly anything for certain, but we're far, far more confident about some things than others. If this leaves people feeling lost and insecure, then that would be a good start. Perhaps (and I say this cautiously, knowing how damaging bullshit and stupidity can be) then they'd stop the chest-thumping for a moment, begin to realise that not everything can be quantified, and actually learn how to think.

In Theory

Things that are true. Things that might be true but, then again, might not be. The set of things we currently think might be true or might not be true and the methods we use to establish if we think they might be true or not.