The squeeze on public finances finds necessity as the mother of invention in trying to find new sources of funding.

At the same time the ethics of the financial system are under continuing scrutiny, with Goldman Sachs last week accused by a departing executive of being "morally bankrupt".

This month has already seen three events in Scotland which bear witness to the increasingly social and ethical dimension to searches for finance.

Last Thursday, 25 senior figures from ethical investing, the church, local government and academia gathered in Edinburgh to continue building their "vision for a new financial system". The aim of the ethical finance forum, staged by law firm Tods Murray with the Islamic Finance Council (IFC), is to "bring together Islamic and ethical banking as the bedrock to a systemically stable and prudent banking sector".

Graham Burnside at Tods Murray, who has been promoting an Islamic funding solution for the Forth crossing, said: "Our meetings have been exploring models with a socially focused view of lending.

"These draw on ideas of 'impact investment' and 'limited purpose banking' with the aim of providing total visibility and choice as well as a social return."

He said there was a growing sector of society prepared to choose social over purely financial returns.

He added: "A more prudent and socially aware banking system could increase confidence, facilitate business among SMEs and enhance Scotland's financial reputation."

Omar Shaikh of the IFC said: "You cannot mask what has happened to our banking industry over recent years, and our discussions have become even more pertinent against the backdrop of constitutional reform.

"We strongly believe the shared values between Islamic finance, the church and broader ethical banking could provide the bedrock to a more stable and prudent banking sector."

Mr Shaikh said Islamic funds, with their avoidance of financial services and companies with leverage, had outperformed the investment universe and mushroomed globally from £500 million to £1400 billion. Islamic funds favour information technology, energy, materials, and healthcare, at the expense of consumer stocks, telecoms and utilities.

"Their investments are aligned with the real economy, financing real assets as opposed to a high degree of speculation and derivative products," Mr Shaikh said.

Craig Mackenzie, head of sustainability at Scottish Widows Investment Partnership (SWIP), the UK's fifth largest manager of socially responsible investing (SRI) funds with £500m, said: "The challenge is how can we deliver something not just for 10,000 or so SRI customers but something which engages the four million customers in our mainstream portfolios." He said there had been a "positive sea-change" in investor attitudes to understanding non-financial alongside financial returns.

The previous day in Govanhill, Glasgow, voluntary sector groups Cornerstone, Quarriers and CrossReach, backed by Social Enterprise Scotland and the Co-operative and Clydesdale banks, staged a conference to examine social impact bonds (SIBs).

SIBs invite investment from private investors in projects that must achieve defined social outcomes to trigger a return of capital, and The Herald last week revealed how the YMCA in Perth has attracted about 12 small investors and businesses to back Scotland's first SIB.

Scott McKerracher, Clydesdale Bank's regional director for Scotland, said: "The social impact bond model provides an innovative solution to addressing the socio-economic problems that are prevalent in our society, while at the same time making savings for the public purse."

Andrew Muirhead, an ex-banker and founder of Inspiring Capital, said the hard-pressed third sector needed innovative funding models that could attract charitable trusts, companies with corporate social responsibility budgets, and "pen-hovering philanthropists" who hesitated to write cheques, but for institutions and pension funds "we need to create a market first".

He said the financial returns were less important to the target market than making ethical investing opportunities "much smarter and more interesting".

Jeremy Peat, director of the David Hume Institute, said infrastructure costs more in the UK than in any other European country, and prioritising funding through the adoption of transparent criteria would be preferable to "government making decisions in cabals".

Chic Brodie MSP, a former business adviser and now chairman of a cross-party committee on social enterprise, said there was a need for new funding sources and a recognition that "uncontrolled spending in deprived communities had limited, if any, success".

Days earlier, the UK's top institutional investors had gathered in Edinburgh under the aegis of the National Association of Pension Funds (NAPF).

First Minister Alex Salmond appealed to them to invest in Scotland's infrastructure plan, while the NAPF and the Pension Protection Fund are responding to the UK Government's call for pension funds to help bankroll a £20bn national infrastructure programme.

On the Scottish Government's appeal, first reported by The Herald in 2010, Mr Salmond argued large-scale infrastructure investments offered security, a predictable income stream over the long-term, and an ethical investment. "You would be improving the roads, hospitals, schools and housing your clients benefit from on a daily basis."

The catch, however, is that big institutions cannot take on the risk of early-stage projects, as was also made clear at this week's RenewableUK conference in the capital. Without initial backing from the Green Investment Bank, small-scale pilot projects in wave and tidal energy will not happen and the sector will not attract the investment it needs.

The same applies to the construction phase of all new infrastructure. Mr Peat said the only solution was for Scotland to go against the grain of free universal services and accept "pay at the point of use" – in road tolls and charges for new broadband.

SWIP's Mr Mackenzie cautioned that models such as social impact bonds lacked scale, as SWIP would typically need a minimum £10m investment.

He added: "We also need a competitive rate of return as opposed to social return, my guess is that for some time we are not going to see that." However, Mr Shaikh believed there would be a big appetite among Islamic fund investors for a $1bn government-backed bond issued by the Scottish Government.