Isaac

• Joyce's letter to Harriet Shaw Weaver of 15 November 1926: "Parnell ousted Isaac Butt from leadership"

• Isaac: son of Abraham, second of the patriarchs and father to Jacob and Esau. Isaac was fooled into blessing Jacob, the younger son (who had the aid of his mother, Rebecca), instead of Esau, the elder son, when Jacob wore a goatskin on his arms and neck in order to appear as his more hairy brother
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• Isaac Butt: Irish Protestant lawyer who began the Home Rule Party which was later led by Charles Stewart Parnell → buttended
  • Third Census of Finnegans Wake
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• eye-sick: i.e. blind

• Isaac Bickerstaff: a persona or pseudonym used by Jonathan Swift

Commentary

• Parnell and Butt as Shem and Shaun. Shem and Shaun are associated with the bedroom door; this, the fourth of seven clauses in this paragraph, corresponds to "swerve of shore" in the first paragraph, the 4th of 7 elements in a second circuit of HCE's bedroom