People
Politeness is only one half good manners and the other half good lying.
— Mary Wilson Little

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
A cheeky split of politeness into two halves. Half is real good manners, the other half is fibbing smoothly, as when you praise a meal you didn't enjoy. It suggests everyday courtesy depends as much on tactful untruths as on kindness.
Context reviewed