Arcadia is a play written by Tom Stoppard.
- Thomasina Coverly - Thomasina is the young, impetuous genius child of Lord and Lady Croom aged thirteen and later sixteen. Thomasina miraculously theorizes the second law of thermodynamics
- Septimus Hodge - Academic and tutor of Thomasina Coverly, Septimus works on his own research while teaching Thomasina. Septimus falls in love with Thomasina and, after her death, spends his time researching and attempting to prove her theories.
- Jellaby - Jellaby is the distinguished, middle-aged butler of the Sidley Park who delivers many letters.
- Ezra Chater - Ezra Chater is a poet and amateur biologist-neither of which he does particularly well. Mr. Chater's wife is constantly cheating on him and has made her rounds between almost all of the men at the estate. Mr. Chater dies in Malta of a monkey bite.
- Richard Noakes - Mr. Noakes is the gardener who excels at frustrating Lady Croom with his new garden plans, spying on carnal embrace, drawing beautiful pictures of the estate and building an improved steam engine. Noakes has drawn up plans to transform Sidley Park into a classical masterpiece.
- Lady Croom - Lady Croom is the bossy, battle-ax who storms around the estate. There exists two Lady Croom's in Arcadia; however, we only meet one—the Lady Croom of the early nineteenth century. Lady Croom is perceptive of all things and knows all happening on the property.
- Capt. Brice - Captain Brice is the sea captain, apparently in love with Mrs. Chater. Brice takes Mr. and Mrs. Chater on his sea voyage to Malta, where Mr. Chater perishes.
- Hannah Jarvis - Hannah is the champion of academic knowledge in Arcadia. While her discoveries are less important than young Thomasina's, Hannah has all but rejected any notion of romantic knowledge in favor of intellectual work. Hannah is an author working on the hermit of Sidley Park and is in her late thirties.
- Chloe Coverly - Chloe Coverly is Thomasina's modern day equivalent. Chloe, aged eighteen, seems as perceptive as Thomasina, but lacks the education to have Thomasina's brilliance. Chloe argues that a Newtonian universe would be destroyed by the random nature of sexual acts.
- Bernard Nightingale - Bernard is the modern fool and fop. In his late thirties, Bernard leaps over truth in favor of finding fame for his theory that Lord Byron killed Ezra Chater. The theory, eventually proved false by Hannah Jarvis, brings Bernard great shame and embarrassment.
- Valentine Coverly - Valentine, aged twenty-five to thirty, is still supposedly a graduate student studying mathematics. The son of the Coverly estate, Valentine works out Thomasina's diagram and reluctantly shares Thomasina's genius with Hannah.
- Gus Coverly - Gus is the self-elected mute son of Sidley Park. Gus is a connector and communicator between past and present; Gus intuitively knows where the foundation for the ruined outbuilding is. He dresses Augustus in Regency clothing and gives Hannah the trans-generational apple that Septimus eats. Gus is also present in the historical story—the actor is double cast as Augustus Coverly.
- Augustus Coverly - Augustus, aged fifteen, is double cast with Gus Coverly. Augustus only appears in one scene as Thomasina's troublemaking younger brother who wants Septimus to tell him about sex.
Septimus Hodge and Thomasina Coverly sit in the front room of an old estate in Derbyshire, England. The house is surrounded by beautiful, traditional, and park-like landscape, lush and green. Thomasina, a curious and rather impetuous girl of thirteen, is the student of Septimus, who is twenty- two. Thomasina asks Septimus what a "carnal embrace" might be. Jellaby, the butler, interrupts the conversation. Jellaby brings a letter to Septimus from Mr. Chater. Septimus reads the letter and tells Jellaby to tell Mr. Chater that he will have to wait until the lesson is finished.
After Jellaby leaves, Thomasina asks Septimus if he thinks it is odd that when one stirs jam in his or her rice pudding in one direction, the jam will not come together again if they swirl the pudding in the other direction. In other words, she asks why one cannot stir things apart. Thomasina's question leads to a discussion about Newton's law of motion. Thomasina believes that if one could stop every atom in motion, a person could write a formula for the future. Noakes enters the room, soon followed by Lady Croom, mistress of the estate, and Captain Edward Brice. Lady Croom is very upset by Noakes's plans for the landscaping of Sidley Park. Lady Croom thinks that Noakes's plans are too modern, Sidley park is beautiful and an "Arcadia" as it is.
The scene has changed to the present day, apparent from the clothing of the characters on stage. The action of Arcadia shifts from the early nineteenth century to the present day. The setting is still Sidley Park, but there have been changes in the surrounding landscape with time. The modern day characters, Hannah, Chloe, and Bernard, sit in the same room as Thomasina and Septimus. Bernard Nightingale, critic, comes to meet Hannah at the estate. Bernard is looking for information on Ezra Chater. Hannah is looking for information on the Sidley Hermit, whose death she attributes to the breakdown of the Romantic Imagination. Bernard tells Hannah he wants to collaborate with her on a project. Apparently, Bernard's copy of Ezra Chater's The Couch of Eros belonged to Lord Byron and inside the book there are three documents that have led Bernard to believe Lord Byron killed Chater in a duel. Bernard believes that Lord Byron slept with Chater's wife, which led Chater to challenge Lord Byron to a duel die by his hand. Because Lord Byron left the US in 1809, soon after Chater published his last known work, Bernard assumes he was fleeing.
The play shifts back to the early nineteenth century. It is morning and Thomasina and Septimus sit together in the schoolroom. Thomasina tells Septimus that his equations are only for commonplace manufactured forms. Thomasina wants to create the kind of equations that make nature, such as an equation to make a flower rather than a circle, cone, or square. Captain Brice enters the room, followed by Mr. Chater who stands behind Brice. Chater is still angry with Septimus because he slept with his wife.
Scene four switches, once again, to the present time. Hannah is reading from Thomasina's portfolio and gives it to Valentine to look at. The pages of Thomasina's book are filled with iterated equations or equations that feed solutions of one equation into the next. Valentine is surprised that Thomasina would be doing this because iteration has only been practiced for the last twenty years. In Scene five, Bernard practices his lecture for Valentine, Chloe, and Gus. Bernard is practicing the speech he will give to introduce his new, groundbreaking theory that Lord Byron killed Ezra Chater over a woman. As Bernard begins his dramatic oration, Hannah excitedly enters the room to talk to Valentine. Hannah is still not convinced that Byron killed Chater or even wrote the letters found inCouch of Eros to Chater.
Scene seven switches constantly between time periods with no obvious divisions. The scene begins with a discussion between Chloe and Valentine. Valentine tells Chloe that the universe is deterministic; one might be able to predict everything to come if he had a computer large enough. Chloe interjects that the formula wouldn't work because of sex—people might fancy people who weren't part of the plan or proper formula. Thomasina is now sixteen. Septimus gives Thomasina an essay from the Scientific Academy in Paris that is like Thomasina's own work—the scientist has found a contradiction in Newton's theory of determinism. Thomasina tells Septimus that she was right; the problem with determinism is likely hidden in the author's observations about the action of bodies in heat. Thomasina understands the second law of thermodynamics (which states that heat is irreversible).
Bernard enters the room, followed by Hannah, who is carrying a garden book. Inside the garden book there contains an entry from October 1st that proves that Chater the poet was the same Chater that was killed by a monkey bite in Martinique in 1810; thus, Bernard's theory is destroyed—Byron did not kill Ezra Chater. Septimus enters with an oil lamp and carries Thomasina's primer. Thomasina enters secretively, barefoot in her nightgown, and holding a candlestick. It is the night before Thomasina's seventeenth birthday, and she wants Septimus to teach her how to waltz. Valentine stumbles in and tells Hannah that Thomasina's diagram is of heat exchange. Septimus and Thomasina discuss Thomasina's diagrams, too, while she tries to get him to dance. The music heard from inside the house changes to a waltz, and Thomasina and Septimus begin to dance. Septimus kisses Thomasina on the mouth, and the couple begins to dance again. Septimus sends Thomasina up to bed with a lit candle. Gus enters and gives Hannah a picture Thomasina drew of Septimus, and Plautus that proves Septimus is the hermit. Gus and Hannah begin to dance.
The Gardens of Sidley Park symbolize the transformation and transition between romanticism and classicism. Mr. Noakes wishes to alter the gardens into the picturesque and thoroughly romantic style and means to tear out the gazebo in favor of a hermitage and drain the lake with a newly improved steam engine. Lady Croom accuses Mr. Noakes of reading too many novels by Radcliff, The Castle of Otranto, and The Mysteries of Udolpho (written by Walpole). Mr. Noakes means to transform the green, lush perfect Englishman's garden into an "eruption of gloomy forest and towering crag," Lady Croom describes it as a haunt of "hobgoblins." As Hannah describes it, the garden is a classical painting imposed on landscape or "untamed nature in the style of Salvatore Rosa … everything but vampires". The garden represents romanticism, (for Hannah) a decline from thinking to emotion, and the need for "false emotion" and "cheap thrills."
The modern day characters wear the Regency Clothes or clothes that would be worn to a fancy dress ball in Thomasina's time. Regency Clothes symbolize high society and privilege. The dress not only links the two generations and time periods, but it reveals the hay day of the English aristocratic family. Chloe, Gus, and Valentine wear thefits to have their pictures taken and dress for the annual dance. The dress reestablishes their power as a family and role in the community, seemingly diminished in modern times.
The Primer is the symbol of learning and academia. Thomasina is the first to use the primer, which once belonged to Septimas; however, at the conclusion of the play, Septimus has taken back his primer. Septimus's use of his the primer once again symbolizes his return to being a student; this time he is a student of Thomasina, who has surpassed his knowledge and teachings.