Inspired by Sally Rooney’s novel Conversations with Friends, as well as the post-lockdown return to socializing, the theme of London’s annual literature festival is Friendship. The 10 days of festivities include talks that focus on the meaning of friendship, with unique perspectives coming from the neuroscientist Anil Seth (October 21), the journalist Anne Applebaum (October 26) and the violinist Patricia Kopatchinskaja (October 26). Dozens of authors will also give talks: the festival’s opening day includes one titled “Common Ground: Friendship in the City of London,” with Caleb Azumah Nelson, Vanessa Onquemezi, and Naomi Ishiguro (Kazuo’s daughter). If you can’t make it to London, you can catch much of the action online. —J.D.