Logic Problem 1

The following is an example from Sir Arthur Conan Doyle's famous detective, Sherlock Holmes, in the story The Cabman's Wig, as found in Tantalizers, by Martin Hollis.

'The problem as I see it,' said Watson, 'is whether the Bishop is telling the truth.'

'Agreed, my good Watson,' exclaimed Holmes.

'If he is then so is the Colonel.' said Holmes.

'The Colonel and the Doctor are not both telling the truth,' Watson continued.

'Agreed again. Nor are the Doctor and the Engineer both lying. If, however, the Engineer is telling the truth, then the Colonel is lying.'

'But,' Watson persisted, 'we still don't know whether the Bishop is telling the truth.'

'Do we not, Watson?' enquired Holmes.

Can you deduce whether the Bishop is lying or not from the information that is available to you and to Holmes and Watson?