I put Austrian in brackets because it is arguably racist to suggest that an entire nation believes this naive, ideological, illogical fringe theory.
By and large, economics is not a science because most economic assertions are impossible to test in a proper scientific controlled experiment.
But some economic theories CAN be tested. In particular, theories about what the buying-and-selling behaviour of people regarding prices. You can often just gather people in a room, set up a particular situation, and observe how they behave in relation to this situation.
This is known as the practice of behavioural economics. It is one of the very few areas of economics where guesswork and speculation take a back seat to hard and fast experimentally verifiable and falsifiable facts. Dan Ariely is currently the king of behavioural economics, he is the Keynes, Smith, Friedman, Marx and Galbraith all rolled into one of the scientific economics field.
How does this relate to von Mises, his acolytes and their theories? I shall explain.
Austrian economics (and conservative free-market economics in general) boils down to this: everything will be wonderful provided all economic actors are sufficiently flexible in price. Sellers mst react to price signals by lowering prices until a market-clearing event occurs. Workers must lower their wage requirements. Banks must call in their loans. Everyone, regardless of their economic situation must settle for whatever can be achieved in the present moment.
The problem is that the behavioural economists have demonstrated beyond any doubt: this is utterly contrary to human nature. Human beings are extremely inflexible regarding prices. We are, in fact, utterly irrational when it comes to making price decisions.
There are two particularly relevant economic phenomena to this: Price stickiness (people refusing to accept reality and demanding an inappropriate price, and obstinately refusing to concede to the new price) and Money illusion (people mistaking inflation for a real increase in wealth, and spending as if their wealth had really increased). You need to look them up, if you are interested in economics, because they change the game.