Quincas Borba
Machado de Assis
the doubt about the philosopher's sanity, which the letter of Saint Augustine leaves open (chapter X), the voice Rubião wonders may be the dog's and dismisses (chapter LXXIX), Napoleon III's beard (chapter CXLVI), the delirium in the coupé (chapter CLIII), the mania that spreads (chapter CLV), the parade on Rua da Ajuda (chapter CLXXXII) and the crown only Rubião sees (chapter CC).
The Idiot
Fyodor Mikhailovich Dostoevsky
Rogozhin's holy fool (ch. I of Part One), the idiot the prince himself says he once was (ch. III of Part One), his confession that he knows people take him for an idiot (ch. VI of Part One), the light that precedes the fit on the hotel staircase (ch. V of Part Two), the two intelligences Aglaya speaks of (ch. VIII of Part Three), the fit in front of the guests (ch. VII of Part Four), the question of whether Nastasya is mad (ch. VIII of Part Four) and the narrator who imagines Schneider saying the word again before the prince beside the body (ch. XI of Part Four).
Don Quixote
Miguel de Cervantes
the gentleman who loses his mind from so much reading (chapter I of Part One), the penance of Beltenebros done without cause and by method (chapter XXV of Part One), the cage accepted as enchantment (chapter XLIX of Part One), the priest and the barber who test the cure and watch it unravel (chapter I of Part Two), Tomé Cecial's question about which madman is the madder, the one who is so by force or the one who is so by choice (chapter XV of Part Two), the diagnosis of a madman interspersed with lucid intervals (chapter XVIII of Part Two), the praise of madness from Don Antonio Moreno after the defeat (chapter LXV of Part Two), and the free and clear judgment of Alonso Quijano (chapter LXXIV of Part Two).
One, No One, and One Hundred Thousand
Luigi Pirandello
the first madman's laugh before the mirror (chapter VII of Book I), the lucid awareness of madness (chapter II of Book IV), the royal road of madness (chapter IV of Book IV), the crowd's cry of «madman» (chapter VII of Book IV), the commitment Firbo proposes (chapter I of Book V), the father-in-law who flees shouting (chapter IV of Book VI), the madman on the terrace to whom Vitangelo says «Like me» (chapter VII of Book VII), and the judge who looks at him as at an incurable patient (chapter II of Book VIII).
Hamlet
William Shakespeare
the feigned madness of Hamlet in scene 1 of Act II, the armed meeting with Ophelia in scene 1 of Act III, and the madness of Ophelia in scene 5 of Act IV.