Science fiction has only recently become a respectable topic for academic study. Much of that study has been informed by Marxism and other radical theories and there is probably no other area of literary study where Marxist critics have done so much to set the agenda. Students will find a basic knowledge of SF useful at many different points in the humanities, not to mention the sciences.

However, for new students the academic criticism of SF can be daunting. The kind of Marxism found in literary and film theory can seem unrecognisable to active socialists and even to Marxist economists and historians. The texts, films and shows selected for analysis often give an impression of the genre that's hard to square with what SF fans and casual readers will have formed for themselves.

To some extent this is unavoidable. Films such as Blade Runner or The Matrix are bound to be more interesting to theorists than, say, Star Wars or The Day After Tomorrow. Writers such as Ursula Le Guin, Philip K Dick and William Gibson will be more closely studied than, say, Lois McMaster Bujold, Arthur C Clarke and Justina Robson, all of whom are popular, thoughtful and thought-provoking. Literary criticism is a specialised field, which since the 1970s has undergone one theoretical upheaval after another. And the record of attempts to apply the insights of historical materialism to literature and culture, though rich, has not always been happy.

Ever since SF became a self-aware genre in the pulp magazines of the 1920s, it has been shaped by criticism from its readers and by interaction between its writers. In fact, that's precisely how it became aware of itself.

Beginning with letters to the editor, expanding into review columns, proliferating in self-published fanzines, fan and editorial criticism focused on questions of scientific plausibility and narrative strength and culminated in the 1950s with the influential essays of SF writers Damon Knight and James Blish. In their hands, fan criticism moved from holding SF to the levels of competence routinely achieved in other popular genres such as crime fiction to measuring it against the sterner standards of mainstream literature.

The next step was to apply to SF the methods of mainstream literary critics such as FR Leavis, Northrope Frye and William Empson. These were deployed to scathing and salutary effect in the 1960s and 1970s by John Clute, M John Harrison, Samuel R Delany and others. At that time, many SF authors were experimenting with techniques - stream of consciousness, fragmentation, unreliable narrators and so on- that had been familiar since the 1920s in modernist literary fiction. Story content was updated more radically still, in tune with the concerns and revolutionary upheavals of the time. This convergence of criticism and creation quickly became known as the New Wave. In technical and critical sophistication, SF had at last caught up with the 20th century.

That century, along with its literature and criticism, turned out to be a moving target. The 1970s saw structuralism, then post-structuralism, shake up the study of literature. Shockwaves from feminism, Marxism and postmodernism followed. Darko Suvin's Metamorphoses Of Science Fiction (1979) drew on the Marxist aesthetics of Brecht for its central concept - cognitive estrangement - in a pioneering and rigorous theorising of the genre. H Bruce Franklin's unabashedly Marxist-Leninist study of Robert Heinlein appeared in 1980. The fiction and criticism of Joanna Russ gave vigorous voice to radical feminism. More recently, Donna Haraway and Frederic Jameson have drawn on SF themes for critical theory and have brought critical theory to bear on SF. A once marginal genre has become a serious topic of academic study and an essential reference point in discussions of the fast-changing present.

What makes the recently published The Science Fiction Handbook, edited by Nick Hubble and Aris Mousoutzanis, particularly useful is that it enables someone unfamiliar with SF and unfamiliar with critical literary theory to find their way into both.

The history and current state of the field itself, as well as of its criticism, is clearly and accurately surveyed, with key terms defined and landmark texts outlined. Film and other media are competently covered and the contribution of fan criticism is given due recognition. The political controversies over race, gender and sexuality that continue to roil the genre's many communities - particularly online and around SF organisations and conventions - are taken seriously, including in how they affect which works of SF we see as significant.

SF sets out to imagine different worlds and futures. Its own future is at every moment being changed by the real world - often painfully, but for the better. This book is a welcome, and welcoming, introduction and contribution to that uneven progress.

The Science Fiction Handbook is published by Bloomsbury, price £19.99. Ken Macleod's latest novel Descent is published by Orbit, price £19.99.