Exact sciences come with the benefit of pure empirical validation. We test, we measure, we assess, and our theories live or die by what we observe. This kind of purity, rooted in the concept of duality or difference, ensures that our compass is always pointing in the clearest direction we can see subject to our current understanding. If something doesn't make sense, we revise our understanding with further testing and observation, which feeds our theories, which are subsequently re-tested and re-evaluated, and so forth.

This is why everyone (okay, almost everyone) loves science. It's precise. It gives us knowledge, and with knowledge comes control over the future.

Social sciences, however, behave a little differently. While the likes of Ludwig von Mises might argue that social sciences generally consist of a priori and axiomatic logical descriptions, I don't really like to look at it that way. The reason I don't is because that description carries with it the implication that truth in social sciences is actually knowable. I'm not so sure it is.

Easy there, big fella, I haven't gone all wishy-washy, post-modernism on you. I still believe in an objective truth, just as I always have. The thing about social sciences is that there is no real truth there to determine, objectively or otherwise. Let me explain.

Psychology, For Example
Freud may want to interpret your dreams using a framework of psychoanalysis. He might even listen to you, hear you, understand you, and give you information that helps you heal. But still, there is no one, correct way to interpret a dream. Sometimes a cigar is something, and sometimes it's just a cigar. It's not as if a more well-honed theory will tell you when a cigar is or is not a cigar. Rather, it's a question of what the psychoanalyst's intellectual framework is, and how well it fits the needs of the listener. There's a bit of a matching-model involved. Maybe Dr. Jones and his analytical framework can help you. Or, maybe what you really need is Dr. Smith's model. And even if you do need Dr. Smith's model, it doesn't mean someone else wouldn't be better off going to see Dr. Jones rather than Dr. Smith, dig? This is why many therapists encourage patients to shop around a bit; they know that their approach works for some patients and not for others.

And that's okay, because there isn't a single psychological truth to discover. It's really about finding the theory that frames your situation in a way that provides clarity and comfort. Here, have a cigar...

Economics, For Example
Considering what I just said about psychology, it should come as no surprise that I am starting to lose interest in the various economic-theory disputes out there. It's ludicrous to argue about whether or not we're in a liquidity trap. It's pointless to banter about Keynes-versus-Hayek. And those New Classicals don't have it all straight, either.

The reason everyone's wrong isn't because economics is worthless or that I have another preferred theory that I think is true. Rather, there is no one, great economic truth to know, thus the objective truth itself is unknowable in this situation, too.

Economic theories are still incredibly useful - all of them. The Keynesian models, old and new, both provide an interesting intellectual lens through which to interpret some of the economic events that occur during our lifetimes. So does the Austrian "model," and all the others. But no one theory or approach is going to explain everything about the economy, that would be pretty stupid. No one expects that "science" will eventually discover an econometric model so precise that it can predict tomorrow's economy within a few standard deviations.

Instead, we experience life, and economic events along with it. We can make sense of many such events by applying the various intellectual frameworks, the economic theories and macro models, and paying attention to what clarifies and what does not. Your favorite model may apply perfectly today; it may not apply at all tomorrow, and it may not have yesterday.

The key seems to be matching things up. We must match the economic theory and the situation based on what provides clarity and good predictions. When something outlives its usefulness, we can set it aside. At all times, though, we should be working to match the circumstances to the model that best describes it.

When we don't have the benefit of applying an exact science to our quest for knowledge, we have to make due with weaker theories. That's fine, they can still shed light on our situation. But remember: they also might not be useful at all. Weber's explanation for today's sociological trends might make no sense to you whatsoever, and if not, there's no sense forcing a square peg into a round hole, so to speak. Apply the theory that fits, then revise as you go. When a theory outlives its usefulness, find a new one.

Hard science provides empirically validated theories. Social sciences provide framing, intellectual models that can help make sense of a situation. The model is not the truth; it's not even close to the truth. It doesn't even function as a source of knowledge. It's just there to help you see things clearly. And if it's not helping you see things clearly, you should find a new one, because it's not the law, it's just a framework.