Lying is much in the news as the moment and we have turned to Principles of Politeness and of Knowing the World, compiled from the letters of Lord Chesterfield, with comments by the Rev Dr John Trusler in 1775, for some 18th-century insights on the matter.

Trusler’s contempt for liars is magisterial: “Of all the vices there is no one more criminal, more mean, and more ridiculous, than lying. The end we design by it is very seldom accomplished, for lies are always found out, at one time or other…Lies generally proceed from vanity, cowardice, and a revengeful disposition, and sometimes from a mistaken notion of self defence…If a man lies, shuffles or equivocate, (for, in fact, they are all alike) by way of excuse for anything he has said or done, he aggravates the offense rather than lessens it… Besides, lying, in excuse for a fault betrays fear, than which nothing is more dastardly, and unbecoming the character of a gentleman.”

“There are persons also, whose vanity leads them to tell a thousand lies... These persons are foolish enough to imagine, that if they can recite any thing wonderful, they draw the attention of the company, and if they themselves are the objects of that wonder, they are looked up to as persons extraordinary. This has made many a man see things that never were in being, hear thing s that never were said, and achieve feats that never were attempted, dealing always in the marvellous…”

No doubt Lord Chesterfield and the Rev Trusler would be appalled by the extent to which lies have now entered public discourse, and by the fact that people who lie do not necessarily face universal calumny or enforced resignation, even if their lies are widely acknowledged and pilloried. After all, as Trusler points out: “There is nothing more manly, or more noble, if we have done wrong, than frankly to own it. It is the only way of meeting forgiveness.”

They identify several very recognisable reasons for lying: malice (telling lies in order to injure somebody’s reputation); vanity (exaggerating achievements, making unverifiable claims); self-defence (telling lies as a way of evading condemnation for inadequacies or incompetence).

Any reader who cursorily examines this list will be struck by the fact that these kinds of lies are very commonly displayed by young children, who recklessly blend fantasy and exaggeration with strict truth, boast sinfully, and whose knee-jerk response, when challenged with any kind of wrong-doing, is to go for wide-eyed, innocent denial. We identify these undesirable traits early, and work hard to socialise our children into behaving more honestly and responsibly. They very quickly learn that their wilder fantasies and fabrications really don’t hold water, and that any self-respecting parent or teacher is going to be deeply suspicious of their outright denials and outrageous excuses when they are caught red-handed.

So it’s a very bad sign when this kind of behaviour makes it into adult life, especially when it is manifested by people in positions of power and responsibility. But maybe we should also take some responsibility – as parents we do our utmost to call out our children when they are caught in a lie, so we really should muster the same level of outrage when a powerful adult falls into the same trap and add our voices to the chorus of disapproval.

On a more everyday level, if you suspect somebody else of lying there are three ways of dealing with it. You can ignore it: the lies are probably more to do with the insecurities and problems of the liar than they are to do with you, and as long as they do not have a severe impact on other people they can just be overlooked. Or you can turn to forensic questioning, then sit back and watch the liar tie themselves in knots and become ensnared in a tangled web of their own making. Finally, if they’re a loved one or a good friend, you stop them in their tracks and save embarrassment with a mild “come off it”.

We will let the Rev Trusler have the last word:

“Remember then, as long as you live, that nothing but strict truth can carry you through life with honour and credit. Liars are not only disagreeable but dangerous companions, and when known will ever be shunned by men of understanding. Besides, as the greatest liars are generally the greatest fools, a man who addicts himself to the detestable vice, will not only be looked upon as vulgar, but will never be considered as a man of sense.”