Stoicisim, the 2,300-year-old philosophy based on enduring hardship, is being rebranded for the 21st century and gaining traction as a modern-day life hack.

Developed by ancient Greek and Roman philosophers, stoicism is underpinned by the use of self-control to combat destructive emotions. In other words, it is comparable to the mantra "keep calm and carry on".

Author Ryan Holiday is leading the charge for stoicism to become a tool for coping with the pressures of modern life.

Holiday explains on his website that: “the philosophy asserts that virtue (such as wisdom) is happiness and judgment based on behaviour, rather than words. That we don’t control and cannot rely on external events, only ourselves and our responses.

“Take obstacles in your life and turn them into your advantage, control what you can and accept what you can’t.”

In a separate piece for Observer.com, he argued that our “’negative’ experiences are often the most useful and valuable experiences of our lives. So, to try to constantly avoid negativity ultimately hinders us.”

His theories are laid out in The Obstacle Is the Way: The Timeless Art of Turning Trials Into Triumph, which tackles modern issues such as anxiety at work and success.

As a former public relations officer for controversial clothing firm American Apparel and the author of a book on self-promotion entitled Trust Me, I’m Lying (described as "chilling" by the Financial Times), Holiday is an unlikely representative for the ancient philosophy.