"The definition of insanity is doing the same thing over and over again, but expecting different results" : Albert Einstein
While there's a bit of conjecture over whether Albert Einstein actually uttered these words, the quote comes in handy when considering the many cases of unlawful and unethical behaviour levelled at Australia's big four banks.
Inquiry after inquiry, committee on to top of committee, enforceable undertakings, slapped wrists, tough talk from the corporate watchdog, solemn commitments on the importance of "culture" from banking bosses.
To regular people getting on with their lives and trusting banks to manage their money, mortgage and superannuation it all sounds like the same answer - or "non answer".
For most it adds up to the same result Albert Einstein is attributed with talking about - the expectation that whatever banking bosses say about the misdeeds that have come to light there's a high certainty there are more skeletons in the closet that bank spin machines are trying resolve internally.
So how to get the to unvarnished truth about the culture inside Australia's banks as scandals continue to mount with alarming frequency and could, as Bill Shorten suggests, a Royal Commission be the answer?
To date, despite the plethora of inquiries, there seems no stop to the bad news coming out of banks as evidenced just last week when Westpac was dragged into allegations surrounding the rigging of the bank bill swap rate or BBSW.
While ASIC uncovered the alleged Westpac behaviour and is taking the bank to court, most other scandals have only come to light through the courage of whistleblowers who have paid a high personal and professional price for coming forward.
Whistleblowers were critical in revealing unethical practices at the Commonwealth and National Australia Banks. And more recently, the chief medical officer at the CBA's insurance arm Comminsure Dr Benjamin Koh put his job on the line and was ultimately dismissed after raising allegations about the appalling treatment of clients and staff alike.
As we have seen in the Royal Commission into child sexual abuse, whistleblowers and victims have come forward with painful evidence and personal experiences that might have been difficult or unthinkable while the institutions themselves, regulators or police were controlling the high emotion inquiries.
So while Bill Shorten is of course a politician sniffing a chance of winning office, he knows the public sentiment has turned against the banks and that demands will only grow louder for any inquiry that has teeth.
The spin from federal government ministers that the corporate regulator ASIC is best placed to investigate rings hollow given the findings of a 2014 Senate inquiry that ASIC is a "timid, hestitant" regulator.
For Jeff Morris - the whistleblower who brought the CBA's financial planning scandal to light - a Royal Commission is the only solution to restore confidence in the banking sector.
"Eight years ago, when I saw what they (the CBA) were doing to some people in that financial planning area, I realised just how bad things had become in financial services," Mr Morris told AM.
"And I kind of thought: this is where we're heading. I thought for many years there needed to be a parliamentary inquiry to lead to a royal commission. And I've never lost hope in that."