Josh Littlejohn is famous for being an entrepreneur with a social conscience. But when he left education, Mr Littlejohn - who co-founded a chain of sandwich shops and a restaurant to help the homeless - did not know what a social entrepreneur was and thought business could only be about profits.

Mr Littlejohn - a keynote speaker at this September’s Scottish Learning Festival in Glasgow - is calling for schools to steer their pupils away from the “one-dimensional idea” that success equals money.

Earnings league tables - charts that allow you to compare the wage of a doctor and a lawyer, for instance - were prevalent when he was at university, but, he argues, money is just one factor that should be considered when it comes to settling upon a career path.

People are motivated by more than just cash, Mr Littlejohn says. They are compassionate and altruistic, and schools must, therefore, show them that business jobs can be about these things, too.

It was only by chance - he picked up the right book at the right time - that he was introduced to the idea that you can run a business through which society profits. Mr Littlejohn, 30, says: “[Money] is just one dimension, one way of looking at the world. [Pupils] should be encouraged to explore the different motivations we all have.”

Mr Littlejohn also believes that schools should teach entrepreneurial skills. The economy is unpredictable, he points out - so it is better to have school leavers equipped to become the employers, not just the employees. “You just never know what the economy is going to be like when you come out of education, so it would make sense to have more people able to make their own opportunities, be entrepreneurial and be the employers. Rather than teach people how to make up the workforce, you teach them how to shape the working world,” he says.

US academic Yong Zhao put forward a similar argument at last year’s festival, arguing that what was needed in schools was an entrepreneurial mindset, allowing children to develop the ability to “invent their own jobs”. When Mr Littlejohn set up his first business, it was about making money because that was the only definition of business he knew. But then he stumbled on Creating a World Without Poverty: social business and the future of capitalism by Nobel Peace Prize-winning economist Professor Muhammad Yunus. Professor Yunus describes the idea of a “social business” - a business created to solve social challenges.

Careers guidance in schools has come in for criticism. Last year, one father reported that Scotland’s careers advice website, My World of Work, had told his academically-gifted daughter to consider being a chimney sweep.

Careers education has also received more government investment and there is an expectation that it will be delivered from age 3 to 18. Last year Tes Scotland reported that the number of careers advisers had increased by 25 per cent since 2013-14 and the number of work coaches had more than doubled.

When Mr Littlejohn left university he applied for the civil service. But he was unsuccessful and set up an events company instead. Eventually, he sold an event for £40,000, providing the cash to set up the Social Bite sandwich shop in Edinburgh. There are now five branches. More recently, Mr Littlejohn opened Home, a restaurant in the capital. The businesses now employ over 100 people, giving all the profits to charity and providing 100,000 items of free food a year via their “pay-it-forward” schemes, which allow customers to buy food for homeless people. Mr Littlejohn is currently building a “village” for the homeless in Edinburgh.

He returned recently to his alma mater, Stirling’s McLaren High, to speak to pupils. His message? “If you set your mind to something, you can achieve anything.” He says: “A lot of people find it quite crazy, all the big name people - all the Hollywood people - we’ve managed to get [to support us]. But I made the point that I went to the same school as them. I had no connections to these people, and no position to do that from.”

Josh Littlejohn will be speaking at the Scottish Learning Festival in Glasgow on Wednesday 20 September. For details visit slfexhibition.com