Like a lot of documentaries about the economics of society, your knowledge of the topics here – to say nothing about how much you agree with them – will depend on your politics.

If you're a conservative you probably wouldn't even give this movie a second glance on the shelf/in your recommendations (depending which decade you live in).

But if you know anything about this world prior to watching this film there's nothing too shocking. You've seen it in movies like Manufacturing Consent and the early work of Michael Moore like The Awful Truth, or if you read magazines like New Internationalist or Nexus.

It's a bit like what Edward Snowden did for the progeny of Project Echelon. If you have half a brain in your head you know how manipulated we are in the media and society by very deep pocketed special and corporate interests in collusion with the government, this movie just shows you the smoking gun.

It basically tells the story about how the modern PR industry works by applying the lessons it learnt from big tobacco. As the title suggests, they wield a very carefully crafted art not of denying accepted truths about issues that come from science, but distracting everyone from the real issue.

A good example is what big tobacco was doing as recently as the 21st century. It was beyond proven cigarettes were terrible for your health – the tobacco companies had suffered embarrassing disclosures in the late 90s revealing they knew as much.

So their new strategy wasn't to convince anyone cigarettes weren't actually harmful, but to reframe the debate into one about nanny states – we're adults, we should be allowed to smoke if we want to without big government regulating us and strangling our freedoms, etc.

Merchants of Doubt shows how the PR industry has taken the expertise learned throughout the late 20th century business climate and applied it to everything from the female sexual response to mobile phones and climate change.

All the usual methods are here, from 'grassroots' citizen groups with shiny websites that are actually funded by pro-fossil fuel or tobacco think tanks to the reams of FOI documents that have until now been buried in dank warehouses.

As always with this sort of thing it's interesting to see competent journalists or documentarians unravel it for you, and you'll smile wryly and shake your head plenty, but it's not really hot news.