In its purest form, post-truth is when one thinks that the crowd’s reaction actually does change the facts about a lie.

The Oxford Dictionaries define “post-truth” as “relating to or denoting circumstances in which objective facts are less influential in shaping public opinion than appeals to emotion and personal belief.”

The story begins at the Plaza Hotel in New York City in 1953. Here the heads of the major tobacco companies came together to figure out what to do in light of a devastating scientific paper that had recently been published linking cigarette tar to cancer in lab mice. The leader of the summit was John Hill, a legendary figure in public relations, who suggested that instead of continuing to fight among themselves over whose cigarettes were healthier, they needed a unified approach where they would “fight the science” by sponsoring additional “research.” The executives agreed to fund this under the auspices of Hill’s newly created Tobacco Industry Research Committee SCIENCE DENIAL AS A ROAD MAP 23 whose mission was to convince the public that there was “no proof” that cigarette smoking caused cancer and that previous work purporting to show such a link was being questioned by “numerous scientists.”