It opens with a chronology of Casanova's life, but this is only in order to give the author licence to abandon chronology from there on, presenting her subject in a series of vignettes, often using the historic present, and centered on a few core themes. Her chapters have subheads like "The Libertine Nun", "A Chance Mishap" and "A Few Days in the Traveller's Life".
She introduces us first to Giacomo as an old man, writing the memoirs (Histoire de ma vie) which are the source of most of our knowledge of him. He is in a castle in Bohemia (the historic present is catching), and starting to feel the effects of time, not least on his sexual potency. He senses that age is making the pursuit of pleasure harder and, worse still, could make the seeker ridiculous; so, rather than striving after love, he has recourse to memory - and miraculously discovers that it allows him to relive the pleasures of the past. This introduces one of Flem's guiding themes: "voluptuousness becomes memory."
Casanova is a voluptuary, but he is not, in sexual terms, a libertine; a Casanova should not be confused with a Don Juan. The libertine aims to seduce. He is concerned with the exercise of power, which even takes precedence over enjoyment; hence the fact that the severing of the relationship, la rupture, is an important stage in the libertine's conquest. Casanova never deliberately breaks with a woman, not does he "conquer" her: he is, in Flem's account, always the seduced rather than the seducer. He experiences pleasure himself only when he is assured that the delights are fully shared. This is a Casanova who likes "nothing better than a woman who shows signs of independence", even writing to one: "Your submissiveness proves to me that you do not love me."
He is also a man of the Enlightenment, the Age of Reason. He strives to make sexual love a pleasure, and would no doubt be surprised to know that two centuries later the word "sexual" is for so many people linked with "problems". What has happened to progress? He is capable of feeling remorse, for example when a combination of circumstances brings him unexpectedly back to his daughter and, for reasons too complex to explain, they end by committing incest; but he is not burdened with any crippling sense of sin. The agonies and ecstasies of Romantic love are equally foreign to him; at most, he feels a sense of melancholy when fate separates him from the object of his affections.
There is more to Casanova and his age than Lydia Flem allows us here: she has little to say about his Freemasonry, for example, or more generally about his attitude to religion; her accounts of his journeys, especially to England and Russia, are concise and she does not mention Casanova's meetings with Voltaire and other figures of the period. Largely because she abandons a chronological account of the life, she is unable to show Casanova reacting to events or developing through time. But all this is outweighed - and even made redundant - by the great merit of this kind of short life, which is that it gives one a powerful urge to discover more.