The Red and the Black
Stendhal
the two loves as the central experiment, and Mathilde's love in chapters 16 to 30 of Book II.
Madame Bovary
Gustave Flaubert
disordered love, and love learned from books in Part I - The Ball as Poison.
The Master and Margarita
Mikhail Bulgakov
Margarita, who goes to fetch the Master at the cost of becoming a witch and queen of the ball, in chapters 13, 20 and 23.
Purgatory
Dante Alighieri
the doctrine of Virgil, in which every act is born of love and only the object and the vigor vary (Canto XVII, Canto XVIII), the good that multiplies when it is shared (Canto XV), the poet who writes what Love dictates within (Canto XXIV), the old love that Dante feels before recognizing Beatrice (Canto XXX), and her accusation that present things led him astray (Canto XXXI).
Paradise
Dante Alighieri
God's will as the sea toward which what he creates moves (canto III), the love of Venus that no longer repents but laughs (canto IX), Poverty as Francis's wife (canto XI), the sea of crooked love from which charity drew Dante (canto XXVI), the circle that is fastest because it is most pricked by love (canto XXVIII), and the Love that moves the sun and the other stars (canto XXXIII).
Don Quixote
Miguel de Cervantes
Marcela and Grisóstomo (chapter XII of Part One, chapter XIV of Part One), Cardenio, Luscinda, don Fernando and Dorothea (chapter XXVIII of Part One), Anselmo and Camila (chapter XXXIV of Part One), Zoraida (chapter XL of Part One), the gentleman in love by hearsay (chapter IX of Part Two), Basilio and Quiteria (chapter XIX of Part Two, chapter XXI of Part Two), and Altisidora (chapter XLIV of Part Two, chapter LXIX of Part Two).
Notes from Underground
Fyodor Mikhailovich Dostoevsky
falling in love by force, out of boredom (Part One, ch. V), the only friend, defeated and pushed away (Part Two, ch. III), the early-morning conversation with Liza (Part Two, ch. VI), the sermon (Part Two, ch. VII), the dream of saving her and having her as his wife (Part Two, ch. VIII), her embrace (Part Two, ch. IX) and the confession that to love was to tyrannize (Part Two, ch. X).
White Nights
Fyodor Mikhailovich Dostoevsky
the condition not to fall in love (First Night), the bundle and the lodger's promise (Nastenka's story, Second Night), the praise for his not having fallen in love and the comparison of the two men (Third Night), the declaration, the love that does not demand to be preferred, and the kiss (Fourth Night), and the letter from someone who wished to love them both (Morning).
Romeo and Juliet
William Shakespeare
love born of hate in scene 5 of Act I, the vows in the garden in scene 2 of Act II, and the potion drunk as a toast to Romeo in scene 3 of Act IV.
Othello
William Shakespeare
the courtship recounted to the Senate in scene 3 of Act I, the reunion in Cyprus in scene 1 of Act II and the kiss before the crime in scene 2 of Act V.