Michael Pollan has brewed tea from opium poppies, quit caffeine cold turkey and tried mescaline, a psychedelic found in some kinds of cactus. While the author’s past works have taken on the Western diet and the cultural attitude toward psychedelics, in “This Is Your Mind on Plants,” Pollan wages a war against — well, the government’s war on drugs. He argues that the approach to regulation has been selective and self-serving, making him “question whether the real rationale of the drug war was ever public health.”

His point? Caffeine was welcomed because it sustained workers and fueled the economy, but psychedelics were criminalized because they were seen as a threat to the social order. Pollan advocates a new drug policy that is driven by science, not politics.

In this conversation, he and Kara Swisher discuss how changing cultural norms around certain drugs may pave the way for better policy and when MDMA therapy might be approved by the Food and Drug Administration.

You can find transcripts (posted midday) and more information for all episodes at nytimes.com/sway, and you can find Kara on Twitter @karaswisher.