Or "why monetary theory can unify austrians and keynesians"
The economics profession is deeply devided. Roughly speaking you have 2 camps, on the one hand the keynesians, who emphasize the contribution of government to the economy and the austrians who de-emphasize it. It leads to virulent discussions for an example of the genre see here (spoiler: it is dumb political bullshit that blames the government and obama).
That divide shows how different hard sciences are to economics. You don't really argue as much in hard science. There is a right and there is a wrong. In economics there is a network of things that interact. The effects of action through the network are diffuse, far reaching and mostly intractable. Furthermore the main fuel of the system, money, tends to exhibit non-linearity that acounts for minsky cycles. See here, for an exponential growth of the money supply.
Monetary theory seems to have fallen in disgrace. Very few academics actually focus on macro monetary theory as it is judged irrelevant. Austrians treat money as if it didn't exist. Keynesians barely scratch the subject. Ironically I had to read marxists to actually make sense of the banking system (critical eye I suppose). Yet the macro cycle, the minsky cycle, receives a huge contribution from monetary levels. As monetary mass increases (say subprime debt) the price of assets run-away in a positive feedback loop (more debt, more money, more expensive assets, better returns, more debt). This is why the initial phase of a monetary minsky cycle is such a political aphrodisiac. Open the money valves and watch your economy grow in nominal and real terms.
It is of note that the mechanism for fabricating money, takes root in the "power-money" emitted by the FED, but really is multiplied in the banking system. It is also of note that traditional, money multiplier models are false in practice. In practice the banking system emits debt and then balances books at the FED with reserves. By regulation, that level of debt should not exceed a certain ratio of capital and reserves. However with credit derivatives such as CDO, the banking system has avoided regulation enacted in the language of accounting of balance sheets by going "off-balance sheet" with derivatives. This in itself wouldn't be a problem, it is in fact a good thing, if it wasn't for the fact that macro monetary levels are out of anyones control. In that context, the private sector, responding to quarterly demands of performance will run the system amock on the way up, and the public sector, responding to 4-5 year terms, will not dare tamper with the system. The system runs unchecked, creating the macro minsky cycle.
So in a way, a monetary link appears between keynesians and austrians. A monetary expansion will create a minsky cycle. Within that minsky cycle (40 years), classical austrian cycles appear (4-5 years) and all the while the government is free to spend (reagan/bush:defense, obama: healthcare) acting both as a catalytic and a stabilizer to the private sector cycles.