Its tone is captured by the oft-quoted line from the preface:
Thompson attempts to add a humanist element to social history, being critical of those who turn the people of the working class into an inhuman statistical bloc. These people were not just the victims of history: Thompson displays them as being in control of their own making. He also discusses the popular movements that are oft forgotten in history, such as obscure Jacobin societies like the London Corresponding Society. Thompson makes great effort to recreate the life-experience of the working class(es), which is what often marks it out as such an extremely influential work.
Thompson uses the term "working class" rather than "classes" throughout, to emphasize the growth of a working-class consciousness. He claims in the Preface that "in the years between 1780 and 1832 most English working people came to feel an identity of interests as between themselves, and as against their rulers and employers."
Thompson's re-evaluation of the Luddite movement, and his (unsympathetic) treatment of the influence of the early Methodist movement on working class aspirations are also particularly memorable. (Thompson's parents were Methodist missionaries.)
Thompson's theories on working-class consciousness are at the core of this writing, and their agency was manifested by way of the core English working-class values of solidarity, collectivism, mutuality, political radicalism and Methodism. Thompson wished to disassociate Marxism from Stalinism and his injection of humanistic principles in this book was his way of steering the Left toward democratic socialism as opposed to totalitarianism.