It has taken almost twenty years since the opening sequence of Trainspotting nailed the problem with the mantra of "choice", but in this election campaign it does seem that politicians have at last tired of serving it up a universally desirable aim.

If any of them are still clinging to the old rhetoric, they might pop along to the Mitchell library tomorrow evening for the Aye Write! literary festival session by former Herald columnist, philosopher Julian Baggini, who will be talking about his fine new book, Freedom Regained: The Possibility of Free Will (Granta, £14.99).

In a thorough exploration of one of the questions that has kept great brows furrowed for the history of humankind, and examines it from the perspective of the Neuroscientist, the Geneticist, the Psychopath and the Waiter, one of the richest chapters is concerned with The Artist's perspective, for which Baggini has specifically sought the wisdom of Turner Prize-winner Grayson Perry. Baggini starts with the observation that it is curious that investigations of free will tend to focus on laboratory experiments or market research rather than the altogether more compelling concept of creative freedom, to which Perry adds a healthy dose of realism about how artistic work is meaningfully shaped by every aspect of the creator's background and existence and pours scorn upon the vision of spontaneous expression as exemplified by Martin Scorsese's short film Life Lessons with its painter of Jackson Pollok-like canvases. Baggini recognises that unconscious creativity is demonstrated in the so-called Outsider Art of people with mental health problems, and is often therapeutic, but he posits, prompted by Perry, that artists are carefully selective from the inspiration of their subconscious. Perry talks of "call and reponse" and of his free will "running on rails". "I'm not suddenly going to start making boring twenty-eight-minute video art because my personality wouldn't allow it," he says, somewhat provocatively.

Baggini expands this beyond the specific experience of the artist with the contention that: "We do not need to be aware of all out thinking to think freely, but we do need to be aware of some of it." That simple sentence contains a great depth of truth, and is a very sane and measured response to the prevalent contemporary notions that we are all at the mercy of the chemistry of our brains or our genes, or that the open access of the internet and social media is unarguably a liberation. And it strikes me as far from insignificant that the philosopher has arrived at that conclusion through consideration of art and the working methods of the artist. He goes on to turn the question on its head by asking Perry what would make him feel that he was losing his freewill, and it is in answering that question that the artist is most often in the front line, and on the front pages. Creative freedom is most often recognised only when it is under threat, whether in Burma or Syria, Ai WeiWei in China or Pussy Riot in Russia. Perry's considered response to the question in his more privileged and less threatened position eschews the metaphysical and identifies the money to make things, the market to sell them, time and good health as being the prerequisites of the exercise of free will.

"We cannot fully develop or express our freedom if we are wholly occupied earning a living or too ill to think clearly," writes Baggini. "Being well and comfortably off are not sufficient conditions for full human freedom, but they are necessary for achieving more than the minimum of it." The politician who can see the value in art when it helps reach such an essential truth is worth voting for.