"It's not merely facts that are under assault in the polarised politics of the UK, the US and other nations twisting in the winds of what some call populism" writes Zia Haider Rahman. "There's also a troubling assault on reason".

He argues that authoritarian tendencies know that warping the facts is only a start. "Warping reason and logic and clarity of thought is the holy grail".

Producer: Adele Armstrong.