Over the last few centuries, the global spread of a vast array of different drugs has reshaped how we work, experience pleasure, fight wars, and explore our inner worlds. And from Richard Nixon’s ‘War on Drugs’ to the opium wars to the scuppering of the hippie movement, those drugs have been entangled with politics and power.

On Downstream, Michael Pollan, author of The Botany of Desire, How To Change Your Mind, The Omnivore’s Dilemma and This is Your Mind on Plants, talks to Ash Sarkar about his experience growing poppies, the cultural politics of peyote, the imperial history of tea, and that one time that Isaac Newton and Edmund Halley dissected a dolphin on a coffee shop table.