Short answers, pulled from the story.
Letters on the English is a series of twenty-four essays by Voltaire based on his time living in Great Britain between 1726 and 1729. The book examines English religion, politics, trade, science, and literature, consistently comparing English freedoms and institutions favorably to their French equivalents.
The French edition, published in 1734, was rapidly suppressed because French authorities viewed the book as an attack on the French system of government. By praising English liberties, parliamentary governance, and commercial culture, Voltaire implicitly condemned French absolutism and clerical power.
The book was first published in English in 1733, followed by a French edition in 1734. A revised English edition appeared in 1778 under the title Lettres philosophiques sur les Anglais.
Voltaire devotes the first four letters to the Quakers and praises the simplicity of their faith, specifically their rejection of baptism, communion, and ordained priests. He quotes one Quaker describing the absence of priests as being "to our great happiness," though he also notes concern about the manipulative potential of organized religion generally.
Voltaire dedicates three letters to Newton's work, covering his law of universal gravitation, his optics, and his work in geometry and historical chronology. He also addresses the comparison between Newton and Rene Descartes made in a eulogy by the French philosopher Fontenelle after Newton's death in 1727, arguing that Descartes deserved recognition as a great philosopher and mathematician as well.
Some scholars compare the two books because both involve an outsider explaining a nation to itself in flattering terms. Voltaire's depictions of English culture, society, and government consistently treat their subjects favorably when measured against French equivalents, much as Tocqueville would later explain American democracy to French readers.