Austrianism is a rationalistic theory of economics. By rationalistic in this context I mean it's not empirical. It's the sort of thing you get when smart people sit around and reason through something and come to a conclusion based on that alone without bothering to observe, experiment, or evaluate their ideas in practice.
A wonderful classical example of this kind of rationalism is Aristotle reasoning that heavier objects fall faster than lighter objects. Of course they do! Heavier objects are subject to more force, therefore they fall faster. It's perfectly rational.
BTW I'm not saying that other economic schools of thought have it all correct either. They clearly continue to make incorrect predictions all the time. I really don't think anyone understands economics very well. It's a subset of complex auto-adaptive systems, but with an added layer of adversarial behavior. In economics when a major economist, government, central bank, or business makes a prediction, the market acts so as to attempt to invalidate that prediction. Economic systems actively attempt to invalidate theories about them.