Terence Rattigan's In Praise of Love is a play about a husband and wife who, with the best of intentions, deceive each other over the wife's fatal illness. It was based in part on the relationship between Rattigan's friend, the actor Rex Harrison, and his wife Kay Kendall, who died of leukaemia. The play was first produced as a one-act play under the title After Lydia in a double-bill with the short farce, Before Dawn, at the Duchess Theatre, London, on 27 September 1973. Rattigan reworked and extended the play as In Praise of Love for its New York premiere at the Morosco Theatre on 10 December 1974, starring Rex Harrison himself.
The play is set in a small flat in Islington in north London, the home of Sebastian and Lydia Cruttwell. Sebastian was a once-promising novelist, now a critic with Marxist sympathies. His sardonic indifference is tolerated amicably by Lydia, an Estonian refugee, whom Sebastian married after the war to secure her a British passport, and whom he seems absent-mindedly to have neglected to divorce ever since. But Lydia is dying: she has been diagnosed with advanced polyarteritis and is unlikely to live more than a year. She confides all this to a family friend, Mark Walters, but, wanting to spare him anxiety, not to Sebastian. Sebastian, however, admits to Mark that he knows all about the illness, and has been keeping Lydia in a state of what he believes to be sublime ignorance. The diagnosis has made Sebastian realise how much he loves his wife, though the need to persuade her that everything is normal has forced him painfully to continue a subterfuge of cantankerous off-handedness. Mark, caught between the loyalties of his old friend and the woman he has always loved, points Lydia towards the truth.
The Duchess Theatre premiere was directed by John Dexter with Joan Greenwood as Lydia and Donald Sinden as Sebastian.
The complex relationship between the action of the play and the real-life story of Rex Harrison and Kay Kendall is examined by Rattigan scholar Dan Rebellato in his introduction to the Nick Hern Books edition (2001). Rebellato traces the play's evolution as Rattigan reworked it for the New York premiere in which Harrison took on the part that he'd originally inspired, concluding that In Praise of Love is 'Rattigan’s last attempt at a well-made play and one of his best'.