The campaign, which will also feature on the Tube, is backed by the British Humanist Association and prominent atheist, Professor Richard Dawkins.

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He also mentioned the atheist Professor Richard Dawkins, whose comments about the Earth's diversity Dr Williams said reflected the feeling of the Spanish saint, St John.

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The festival takes place in Salford, Greater Manchester, on Wednesday and Thursday and will include a debate on the relationship between science and religion between Professor Richard Dawkins and the country's Chief Rabbi, Dr Jonathan Sacks.

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In response, Professor Richard Dawkins, a high profile atheist, was asked to broadcast an alternative Thought for the Day , but his thought - that "we have been born and we are going to die, but before we die we have time to understand why we were born" - was broadcast in a different slot on the programme.

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