There's a passage at the start of Britten's opera Billy Budd when the aged Captain Vere, introducing the tragedy that's about to ensue, angrily rails at God because “there's always some flaw, some defect” in what seems to be a perfect human being or a paradise-like situation. Bizarrely, but perhaps significantly, that line flashed into my mind as I perused the brochure for a four-day arts-and-craft festival in Oxfordshire called Art in Action.

At first glance, it is perfect. It brings together more than 200 creative artists - ranging from sculptors and painters to glass-blowers, woodworkers, ceramicists, gardeners and even musicians and actors who give performances during the event. There can't be a more concentrated gathering of craftspeople in the country, and some of them are very distinguished names.

Nor can there be another arts fair taking place in such beautiful surroundings. It all happens (from Thursday) in the grounds of Waterperry House - the gardens created by the legendary horticultural guru Beatrix Havergal in the 1930s and lovingly maintained ever since.

But this festival is far more than a platform for professional crafts- people. Many of the 30,000 people who flock to Arts in Action each year are attracted by the demonstrations and workshops. They offer the chance for people who paint, embroider or sculpt as a hobby to pick up tips from experts. The classes cover everything from engraving and bookbinding to medieval manuscript illustration. And the list of organisations running them includes some of the country's top art colleges. What's more, many classes are aimed at children.

Where, then, is the flaw in this Oxfordshire paradise? What's not to like about Art in Action? Well, tucked away in the glossy brochure is a single sentence telling you that the festival is run by a London-based charity called the School of Economic Science. Indeed, Waterperry House is owned by the SES - and now decorated with a series of giant frescoes that illustrates its philosophies. So what's wrong with that? The answer is nothing - provided that you go to this particular art show with your eyes wide open.

Founded in 1937, and ruled for decades with a rod of iron by the exotically named Leonardo da Vinci Maclaren, the SES promotes a Hindu-related philosophy. In itself that's fine - though its stern emphasis on the negation of individuality does sit strangely with the SES's sponsorship of a huge event that's supposed to foster creativity.

But the SES's methods of teaching its initiates and retaining their loyalties have also prompted charges that it is a kind of cult. I know people who have found the SES to be a helpful and entirely benign influence on their lives; and others who have encountered it and found it weird. Not for a moment do I expect Art in Action to be anything other than a showcase for high-quality craft skills. But as with everything in life, and particularly with the arts, it's as well to know who is paying the piper - even if it's not clear why.

www.artinaction.co.uk