whose The Religion of Nature Delimited (1722) was popular in the first half of the eighteenth century. It propounded the theory that all vice is a species of lying, or in other words that the fault of a wrong action lies in its tendency to give rise to false belief. The theory had the misfortune to be discussed by Hume (Treatise, Bk III, 1, 1) who first admits that ‘a person, who thro’ a window sees any lewd behaviour of mine with my neighbour’s wife, may be so simple as to imagine she is certainly my own’ but goes on to point out that this is hardly my fault, and furthermore ‘if I had used the precaution of shutting the windows, while I indulg’d myself in those liberties with my neighbour’s wife, I should have been guilty of no immorality; and that because my action, being perfectly conceal’d, would have had no tendency to produce any false conclusion’.