By creating a country of entrancing simplicity called Botswana, and a warm-hearted lady detective whose virtues are brisk common sense and some useful homespun philosophy, Alexander McCall Smith has charmed a huge and devoted audience.

Now he tries something more daring: to do the same for Edinburgh. His new heroine is a lady detective whose virtues are brisk common sense and some useful homespun philosophy.

Isabel Dalhousie, who inhabits the respectable Merchiston area of the city, where, indeed, Professor McCall Smith himself resides, may be a touch less warm-hearted than her Botswana counterpart, but she is no less resourceful. When she observes a beautiful young man fall to his death from the upper circle of the Usher Hall, she makes it her business to find out who he was and why he died.

So far, so perfectly McCall Smith. The opening chapter sets the tone immaculately. Ms Dalhousie observes the members of the Reykjavik Symphony Orchestra through her opera glasses and ponders the genetic source of the Scandinavian type; she realises to her consternation that the second half of the concert is to be Stockhausen; she sees, in a split second, a tousle-haired young man plunge to his death upside down, and immediately recalls Auden’s poem on the fall of Icarus. We recognise her immediately.

This is Miss Jean Brodie — as gumshoe. The McCall Smith magic fails, however, to work as well in the genteel avenues of the New Town as it does in the dusty thoroughfares of Gaborone. Unlike Mma Ramotswe, who was an original, Isabel Dalhousie is all too predictable. She is a spinster with a love affair in her past, who employs a sharp-eyed housekeeper, works as an indexer on the Journal of Applied Ethics, does the crossword every morning, and convenes weekly meetings of the Sunday Philosophy Club; or rather — and here we enjoy a chuckle at the professor’s little joke — it has yet to meet.

Edinburgh is just as recognisable. This is a douce city of cafés and restaurants, where you may lunch at the Scotch Malt Whisky Society alongside “direct and open-faced people who believe in fellowship and good humour”, or take in the private view of an Elizabeth Blackadder show, or even attend a concert of the Really Terrible Orchestra (a real group, co-founded by McCall Smith) and hear middle-aged players struggling to read their scores.

Of course, there are mean types — untrustworthy Toby, who opts to wear strawberry- coloured trousers, or the disagreeable Minty Auchterlonie, a pushy financier; but, as Isabel observes, you should never judge a person by appearances.

And here, alas, we run into the principal drawback of The Sunday Philosophy Club: the philosophy. Dalhousie’s musings, which intrude at almost every opportunity, range from the glib to the banal. Hypocrisy — is it inevitably bad? Should private information always remain private? Is it true that boys need fathers to teach them how to behave? Are good manners just a bourgeois affectation, or are they the basic building block of civic society? There is, I fear, much more of this.

Dalhousie should realise that this is Edinburgh, the city of Hume and Ferguson, where we demand high standards of our philosophers. She deserves full marks for her detective work, but we can only hope that the Sunday Philosophy Club remains indefinitely postponed.

THE SUNDAY PHILOSOPHY CLUB by Alexander McCall Smith

Little, Brown, £14.99; 288pp Buy the book from Books First £13.49 including free delivery

The lawman

Alexander McCall Smith lives in Edinburgh. He was born in Zimbabwe, and has lived in Botswana, where he helped to set up a law school. He is a Professor of Medical Law and the author of more than 50 books.

He plays the bassoon, but dislikes “the very high notes”.

E-mail McCall Smith or Mma Ramotswe at www.randomhouse.com/features/mccallsmith/

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