Both Uses of

Puritans
in
1984, by Orwell

The sexual puritanism of the Party was not imposed upon them.†
p. 72.2 *

Puritanism = a religious movement of the 16th and 17th centuries to purify Protestant Christianity of rituals of the Catholic Church, and which stressed hard work above pleasure

Unlike Winston, she had grasped the inner meaning of the Party's sexual puritanism.†
p. 132.9

Definitions:

(1) (Puritans)
English Protestants who in the 16th and 17th centuries wanted more purity and less ritual in worship, and who stressed hard work above pleasure

(a Protestant is any of the Western Christian religious denominations that broke off from the Catholic Church. In the US, the best known are Baptists, Methodists, Presbyterians, and Episcopalians.)
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

As a common noun (not capitalized unless at the start of a sentence), puritan or puritanical can refer to someone who is very strict -- especially about religious principles or proper behavior.