In Praise of Love, originally entitled After Lydia, is the first part of a 1973 double-bill play by the English playwright Terence Rattigan (the second half being Before Dawn, a burlesque of the opera Tosca). It was the penultimate play he wrote.
The play’s action was loosely inspired by the true-life relationship between the actor Rex Harrison and his actress wife Kay Kendall. In the play, the couple are transformed into the egotistical left-wing literary critic Sebastian and his East European refugee wife Lydia. During the Second World War, some 30 years previously, Sebastian had served in military intelligence while the part-Jewish Lydia was with the Resistance and then survived on her wits and her feminine charms; each is shown using the aptitude for deception developed then to try to protect the other from the knowledge that Lydia is suffering from a terminal illness. Rounding out the cast are Mark, a best-selling popular novelist and a friend of Sebastian’s, who has long carried a torch for Lydia, and Joey, the couple’s 20-year-old son, himself an aspiring writer, who is in rebellion against his father’s overbearing manner and professed Marxist views.