The flag has been decided.

The Saltire will fly in an independent Scotland. What, though, would be the iconic symbol of Scotland should we vote Yes in September? What would be our replacement for Britannia?

Despite all the arguing between the No and Yes camps, little thought has been given to this subject. For that alone, we should thank Mohamed Al Fayed, the former Harrods owner, for bringing it to our attention. Whether we should thank him for offering to give Scotland its equivalent of a Statue of Liberty, should the country become independent, is a different matter.

In his view, our symbol should be female, like Britannia, and should personify Scotland's greatest characteristics. These are, he says, courage, foresight and intelligence.

Mr Al Fayed, an Egyptian who owns thousands of Scottish acres, has found a candidate. Perhaps unsurprisingly, she is a pharaoh's daughter called Scota and, according to an ancient and disputed story (myth), common ancestor of the Scots.

Yes, I know. It sounds mildly bonkers, especially the notion that an eight-foot statue of Princess Scota should be erected at Inverness Airport to greet people arriving in the Highlands. But, before we dismiss it out of hand, remember that gifts of iconic landmarks have precedent.

France, for example, donated the Statue of Liberty to New York in 1886. It promptly became the symbol of the city and of the country, seeming to embody all that America offered its arriving immigrants. It mattered little (if at all) that it originated in another country and that the sculptor's mother was the model for Liberty's face.

Also, myth is no disqualification. Remember Hans Christian Andersen's fictional tale of The Little Mermaid? It was the inspiration for the statue of that name in Copenhagen, the first image that comes to mind when Denmark is mentioned.

So, what symbol should a post-independent Scotland have? What values would we like it to embody? If not Scota, then who or what?

For the sake of argument, let's stick with the idea of it being a woman, if only to consign to history a militaristic past. I'm afraid Nicola Sturgeon just won't fit the brief and we don't want to go casting back to Flora MacDonald.

Throughout history there are some outstanding Scottish women, though not as many as we might wish.

There's the Countess of Ross who led her own troops against the English at the time of Wallace. Then there was Black Agnes, who defended her castle for five months in 1334 against the Earl of Salisbury. Dr "James" Barry, surgeon general in 1865, was a woman in disguise. Elsie Inglis was a pioneering doctor and suffragist.

Today high achieving women abound in the arts, sciences, the law and across the professions. Ann Gloag is successful in business and charity. JK Rowling has breathed new life into children's literature. The fact that she's English-born could underline Scotland's openness to outsiders.

These names raise another question. Can any one woman, in whatever era they lived, be the symbol of a nation's future? The same doubt applies to Scotland's greater legion of famous men.

David Hume, the philosopher, has international acclaim, as does Adam Smith. But how would anyone weigh the claim of either against William Wallace, Robert the Bruce, John Logie Baird, Alexander Fleming, Alexander Bell, William Thomson (Lord Kelvin) or James Watt? For that matter what of the recent nobel laureate, Peter Higgs?

Choose any one of these and you will offend those who favour Robert Burns, Walter Scott, Robert Louis Stevenson, Conan Doyle or other candidates from the arts or academia. Would John Muir, for example, be more encompassing as a symbol or Carnegie better represent the past and future philanthropic instincts of the nation?

No. In my opinion, no woman or man, however great, would be sufficient for the role.

You can put Nelson on a column, Wellington on a horse and Queen Victoria on a stone wedding cake outside her central London palace. But it's Britannia, a female personification of this island, around whom the British of all opinions and none can rally.

Similarly, the French have the allegorical Marianne as a symbol of the French republic. They also have the Eiffel Tower. The metal structure in the heart of Paris was constructed to celebrate the 100th anniversary of the French Revolution. For many people it is the most immediate representation of La France.

This prompts the question whether an independent Scotland would need any symbol to take a human form. Would it be better served with an image like the Forth Bridge?

It already has international recognition. It favours no city over another yet speaks of science, of bridging communities and movement forward from an established past.

I think it is a strong candidate. My worry is that it speaks too much of the biscuit tin for a modern nation. Has it been over-exposed along with the thistle, with tartan and heather, the head of a stag and the increasingly ubiquitous saltire?

Walter Scott, who said the easiest thing to invent was a tradition, is credited with forging that now tired image of tourist Scotland. If a new age is upon us we need a new image maker with a tradition or two up his sleeve.

So what is it we are trying to encapsulate?

The American symbol is liberty. The French is the same coupled with fraternity and equality. All three will be needed if there is to be a new Scotland. Since we are perhaps to be a rainbow nation, tolerance would be good in the mix. Then if we are to make our way in the world, industry and innovation, drive and adventurousness will be needed.

What, then, of Scota's candidacy? According to legend, Scota travelled either to Ireland or Scotland back in the mists of time.

So, in her, we have an immigrant adventurer, a stranger to the shores of these islands who looks to the future and spawns an entire people. Could she fit the bill?

The short answer is no.

Scota is an unknown. She carries more weight with her Egyptian promoter than with anyone here. A symbol needs resonance.

And please let no-one even think of the cartoon redhead, Brave.

To symbolise Scotland I think we need to look to nature. We have mountains and lochs aplenty but they are difficult to represent. We also have forests and woodland.

We even have a strong candidate for a national tree. It is the Scots pine - and it would be my choice of symbol.

The Scots pine is magnificent, sculptural, a thing of beauty. It has broad limbs, strong roots and a capacity for survival.

It has been around to witness the twists and turns of Scottish history and, whichever way the referendum vote takes us, it will be around long after we are mere memories to see what is to come.