Perhaps we have to distinguish between manners and etiquette. The latter is largely a matter of instinct and common sense and any solecism rarely important, at least among those of the same cultural background.
It's not easy to define 'bad manners' without recourse to their polar opposite. Taking thought to treat others as we would wish to be treated is one way of determining what's appropriate. But anything that includes making free with the time, space, generosity, person, good nature, possessions of someone else, surely qualifies for the 'bad' list. One of my own particular bugbears is the practice of those who engross time and ruin focus (whether it's on writing or not!) by trying to bully you into wanting their, often spurious, goods and services on the 'phone. I've put a block on those and on robocalls, but they still get through to the extent that I seldom answer the house 'phone on the assumption that anyone important will leave a message.
Many years ago, I remember a light-hearted survey being undertaken on BBC Television by the medical scientist, Sir Peter Medawar, and his daughter, Caroline, in which they canvassed opinion – in real time – it took about three hours! - from around the globe as to what binds human beings together and makes the world tick. The overwhelming concensus was not the stuff of romantic songs. It was 'respect and courtesy'.
We may safely conclude that when such considerations are absent, civilisation falls apart.
Among the following are some pretty impressive claims for the power of good manners. Others are a little more scathing!
A man's manners are a mirror in which he shows his portrait.
Johann Wolfgang von Goethe
Good manners and soft words have brought many a difficult thing to pass.
Sir John Vanbrugh
The hardest job kids face today is learning good manners without seeing any.
Good manners are made up of petty sacrifices.
Ralph Waldo Emerson
Manners are not idle, but the fruit of loyal nature and noble mind.
Alfred Lord Tennyson
Manners are stronger than laws.
To succeed in the world it is not enough to be stupid, you must also be well-mannered.
Civility is not a sign of weakness and sincerity is always subject to proof.
John F Kennedy
Prithee, don't screw your wit beyond the compass of good manners.
No advance in wealth, no softening of manners, no reform or revolution has ever brought human equality a millimetre nearer.
Manners are the hypocrisy of a nation.
Honoré de Balzac
Nowadays, manners are easy and life is hard.
Young man, there is America, which at this day serves little more than to amuse you with stories of savage men and uncouth manners.
Savages we call them because their manners differ from ours.
Fine manners are the mantle of fair minds.
Amos Bronson Alcott
Nothing sharpens the arrow of sarcasm so keenly as the courtesy that polishes it.
Lord Chesterfield (Philip Dormer Stanhope, 4th Earl)
Noble madam, men's evil manners live in brass; their virtues we write in water.
Causes Rosy Cole Supports
World Vision, International Prison Outreach, Salvation Army, Emmaus Project, Poor Clares, DogsTrust, BUAV (against animal testing) WWT (Wildfowl &...