Once upon a time, the educated reader in, for example, the 17th or even the 18th century could load an essential library of classics on to a horse and cart. Even in Victorian times, you could easily masquerade as well-read with a wagonload of books. Today, you might fill a container truck with all the titles you considered to be representative of the western intellectual tradition – and still find yourself playing catch-up.



Today, in what I have described elsewhere on this site as a golden age of reading, there are so many books to investigate, in so many genres: popular culture, anthropology, biography, travelogue, philosophy, reportage, history, memoir and on and on. The discriminating contemporary reader, drowning in ink, both real and virtual, faces an almost impossible challenge. Where to start? How to go on? Where to stop? Thus: the raison d’etre of the popularity of book lists.



Focus on the Anglo-American novel, and the list-making project is not disreputable: it has a discernible literary critical purpose. As I discovered during the two years in which I put together the Guardian/Observer’s 100 best novels in English series, the satisfaction of such an exercise came from the weekly exploration of a teeming, baggy, and multitudinous genre.



Not only did I make many wonderful discoveries within the Anglo-American canon (translations were excluded), the dialogue with our readers – passionate, instructive, confessional and sometimes vituperative – was also enriched by the exchange and debate surrounding a shared literary experience.



As the series got under way in chronological order, dedicated readers following the sequence could easily speculate about my next week’s choice. Sometimes, indeed, they actually influenced future selections, or provided painful reminders of books I had unaccountably overlooked.



Unlike fiction, nonfiction is not a genre. It’s a headache

There was, moreover, an entertaining posse of maverick contributors lobbying hard for impossible choices – books and writers on the wilder fringe of the literary-critical radar. But even at its most contentious moments, the 100 best novels was held together by the loose discipline of genre – its purpose was to examine storytelling, fictional narrative and the imagination. There was, additionally, the artistic glue of the thing called style. Every single title listed had some distinctive stylistic quality that set it apart from its contemporaries; it was plainly unique.



Unlike fiction, nonfiction is not a genre. It’s a headache. Compiling 100 great books of nonfiction in English takes the reader into a universe of titles unrestricted by the limitations of a canon or the strictures of critical theory. Anything goes – so long as it’s in English (once again, to keep things manageable, we have excluded translations).

That, indeed, is the problem with the recent contention that contemporary nonfiction now challenges fiction for seriousness and importance: such a claim lacks definition. Ranging through philosophy, history, belles lettres and biography, one’s responses and choices are much more personal, even capricious, and more contingent on education, background, experience and – yes – sheer prejudice. The emerging focus of a nonfiction list must reflect less a tradition (as in fiction) than the evolving history of Anglo-American relations.



Stepping out of the comfort zone of genre, a nonfiction list quickly encounters some awkward questions. How, first of all, to define “great”? There is, for instance, what I think of as “the Darwin question”. On the Origin of Species will obviously find a place here, as will (spoiler alert) Johnson’s Dictionary, Wollstonecraft’s Vindication, Hume’s History, Woolf’s A Room of One’s Own, and Tom Paine’s Common Sense, or possibly The Rights of Man. But do such choices establish impossibly high criteria ? Are Dawkins (No 10) or Hawking (No 6) to be compared to Darwin? Can Sontag (No 16) or Didion (No 2) be spoken of in the same breath as Woolf or Wollstonecraft?



My answer – by whose uncertain light this series will continue to advance into the shadowy vastness of the literary universe that does not encompass fiction – is that the Anglo-American tradition is a galaxy with many stars. There are meteors of gold, azure and vermillion, but in the background there are also impressive constellations of black, silver and grey.



In the coming weeks, I plan to select self-help and cookery books, reportage and etiquette manuals as well as philosophy and economics. The guiding principle is that all these titles should, in some sense, have made a discernible contribution to who we are today, and to the way we live, think and write. Nonfiction (which is not a genre) also includes (according to library classification conventions) poetry and drama. I intend to choose poets and playwrights as well as polemicists and politicians.



Another, and final, word on the numbering convention employed by this list: we are going backwards from the present into the past, in a reverse chronology, hoping to discover adventitious connections between new and old, modern and ancient, while also varying the readers’ experience.



As this list unfolds, the task of selecting 100 great works of nonfiction does not get any easier. After 20 selections, I am already regretting some omissions: John Berger’s Ways of Seeing; Alex Comfort’s The Joy of Sex; and Janet Malcolm’s The Journalist and the Murderer to name three. Currently, I am struggling with Noam Chomsky’s Syntactic Structures (1957). Very many commentators and critics have singled it out as a book of great importance and influence, which is indisputably true when you read the literature surrounding it. And yet … I have to confess that the book itself is virtually unreadable, and almost impossible for the lay reader to understand. How can a list such as this include a book it cannot explain? Watch this space.

More than most fiction, all these titles bear – often explicit – traces of the times in which they were written and researched. As an informal biography of an evolving culture – initially Anglo, then Anglo-American, and now global – in all its many moods, this list makes its own, fallible stab at an unofficial summary, with the usual caveat that, at the end of the day, it’s just my choice.