Are you experiencing déjà vu? It's a common occurrence among television viewers, particularly in summer when many programmes are repeats. But another cause may be the increasing number of programmes which cover the same ground as one another. For instance, last Friday (repeated on Sunday), BBC2 brought us the second part of Ganges, a series which explores an important Indian river. On Monday, BBC2 offered India with Sanjeev Bhaskar, in which Sanjeev visited Calcutta and the Ganges.

Last Friday, The Insider: Gardens Under Threat (Channel 4) was followed by a Gardeners' World special: The Great Garden Grab (BBC2). Both programmes voiced similar concerns about gardens and allotments disappearing because they are used as sites for building. The Channel 4 programme showed how some ancient allotments in Hackney are being destroyed to build a path for the 2012 Olympics - a path which will only be used for four weeks. The BBC2 programme made the point that, since 1985, gardens have been classified as "previously developed land", which puts them into the category of brownfield sites where developers can easily build new houses.

Talking of covering the same ground, Britain currently seems to be covered with celebrities travelling around and telling us about our beloved country. We've had David Dimbleby, and Coast, and Coast Revisited, and Griff Rhys Jones exploring Britain's highspots. Now we've got the mindless Britain's Favourite View (ITV1) and Robbie Coltrane's B-Road Britain (ITV1), which shows him driving from London to Glasgow on minor roads, "trying to find the real heart and soul of Britain".

Coltrane said that the first programme would take him through "Gloucestershire, Warwickshire and Leicestershire" - which didn't explain why his first stop was in High Wycombe (in Buckinghamshire) where he watched the ancient ceremony of the Lord Mayor being weighed. In fact much of Robbie's journey consisted of watching weird ancient rituals or visiting strange people and places. He called at two pubs in Stony Stratford where the phrase "cock-and-bull story" might have originated (but probably didn't) and went to Cambridge to play tiddlywinks with the university team. Like other comedians on similar journeys, Coltrane is a jokey travelling companion, although he should resist the temptation to say "including moi" which occurred twice in the first episode.

Great British Journeys (BBC2) is another, more rigorous, series in which Nicholas Crane (the man from Coast who carries an umbrella strapped to his rucksack) retraces the footsteps of eight past explorers of Britain. He started by following the route taken in 1772 by Thomas Pennant through the Scottish highlands and islands. Nicholas struggled up the rocky slopes of Beinn an Oir on Jura and looked for basaltic columns on Skye (where Griff Rhys Jones started his Mountain tour a fortnight ago). On the island of Canna he was told that the inhabitants have second sight - one fisherman foreseeing a shipwreck before it happened.

d=3,3,1Second sight is the sort of thing that Richard Dawkins sneered at in The Enemies of Reason (Channel 4). I tend to agree with Dawkins's diatribes against religion but I have my doubts when he adds other things which he regards as irrational. He praised science for such achievements as putting a man on the moon and cloning a sheep (big deal!) but condemned everything that he regards as superstition, including spiritualism, astrology, dowsing and virtually anything that is 'spiritual'.

However, his investigation of these matters was hardly scientific. He dismissed astrology on the basis of newspaper horoscopes, without looking into more serious aspects of astrology. Similarly paranormal and psychic phenomena were rejected without any deep research into these subjects.

Dawkins asserted that "science is always open to new possibilities" but his mind is obviously closed to any possibility that these 'superstitions' might have some foundation. He has elevated science and reason into a fundamentalist faith which cannot tolerate doubt or questioning and ignores feeling and emotion. There are more things in heaven and earth, Richard, than are dreamt of in your philosophy.