"The habit of always saying “please” and “thank you” first began to take hold during the commercial revolution of the sixteenth and seventeenth centuries — among those very middle classes who were largely responsible for it. It is the language of bureaus, shops, and offices, and over the course of the last five hundred years it has spread across the world along with them. It is also merely one token of a much larger philosophy, a set of assumptions of what humans are and what they owe one another, that have by now become so deeply ingrained that we cannot see them."
via How We Got “Please” and “Thank You”: Why the line between politeness and bossiness is a linguistic mirage.
