In 1973 Ursula Le Guin was phoned by publisher and science fiction fan Andrew I Porter, trying to persuade her to write about herself in his magazine Algol. “Andy kept saying things like, ‘Tell the readers about yourself,’ and I kept saying things like, ‘How? Why?’” Standing in her hallway, with a child and a cat circling her legs, it seemed impossible to explain over the crackling connection that “the Jungian spectrum of introvert/extrovert can be applied not only to human beings but also to authors”. Le Guin knew that at one end of the spectrum there are authors such as Norman Mailer, who talk about themselves, and at the other, authors who, like her, need privacy.

When Le Guin died earlier this year, aged 88, the grief and gratitude her readers expressed were overwhelming. Through her Earthsea series, Hainish cycle and many other books she had enriched countless lives, broadened innumerable minds. In her last year, she worked on a selection of her non-fiction – essays, talks, introductions, reviews and meditations – for a British audience. Brief speeches given at the National Book awards ceremony, in 1972 and in 2014, open and close Dreams Must Explain Themselves, framing pieces spanning four decades drawn from previously published collections.

Characteristically straight-talking and unpretentious, Le Guin first introduces the book as “a carrier bag full of ideas and responses, thoughts and rethinkings”. Then moving swiftly from the ordinary to the magical in under half a page she ends by hoping “that readers wandering in this garden of forking paths will find themselves in a rose plot or a bed of mandrake-root or a small grove of mallorns or sequoias where they feel at home”.

The book includes brief sketches of Le Guin’s parents and childhood. She was born in 1929, the daughter of Alfred L Kroeber, founder of the department of anthropology at the University of California, and his wife, the writer Theodora Kracaw. In Indian Uncles (1991), she describes her father’s relation to Ishi, a “wild” Native American who appeared suddenly in a northern California town in 1911, speaking a language local Native Americans did not understand, after hiding with the remnant of his people for most of his life. Eventually, Le Guin’s mother became Ishi’s biographer. Le Guin remarks: “She never wrote till she was over 50 and she never stopped writing till she died at 83.” In contrast, Le Guin describes herself as writing throughout her life. She was 11 when she sent her first (unsuccessful) submission to a science fiction magazine.

In The Princess (1982), originally addressed to the National Abortion Rights Action League, Le Guin creates a fairy story to describe an abortion she had as a student. It captures the support of her parents “who were indeed royal, where it counts, in the soul”, and her retrospective gratitude to all those who have worked for the rights, dignity and freedom of women: “They set me free, and I am here to thank them, and to promise solidarity.”

Later she married the historian Charles Le Guin and had three children. The Fisherwoman’s Daughter (1988) reflects on the struggle to combine writing and motherhood. The author revisits a scene from Margaret Drabble’s The Millstone in which Rosamund is working on a book review, not realising that her eight-month-old baby is eating her flatmate Lydia’s manuscript novel. “Couldn’t she at least have eaten a manuscript by a man?” Le Guin asks humorously, before replying: “No, no, that’s not the point. The point, or part of it, is that babies eat manuscripts. They really do.”

On the subject of menopause, back in 1976, Le Guin complained that it is “probably the least glamorous topic imaginable” despite being one of the very few to retain “some shreds of taboo”. The essay concludes that “it requires fanatical determination now to become a Crone” and she fantasises about sending an old woman from the village marketplace to the fourth planet of Altair to teach the friendly natives about the nature of the human race. Old women, she insists, are the only people to have “experienced, accepted, and enacted the entire human condition”.

Acknowledging her debt to Virginia Woolf, always her “greatest enabler”, Le Guin argued in 1986 for the importance of women “writing, publishing and reading one another, in artistic and scholarly and feminist fellowship”. She projected forward, to the year 2000, and beyond: “To keep women’s words, women’s works, alive and powerful – that’s what I see as our job as writers and readers for the next 15 years, and the next 50.”

Woolf’s A Room of One’s Own was published the year Le Guin was born. Le Guin argues that, “speaking strictly on the evidence”, a room of her own is not necessary for a female writer, although it can be a help. Instead, “the one thing a writer has to have is a pencil and some paper. That’s enough, so long as she knows that she and she alone is in charge of that pencil, and responsible, she and she alone, for what it writes on the paper.”

• Dreams Must Explain Themselves: The Selected Non-Fiction of Ursula K Le Guin by Ursula K Le Guin (Gollancz, £18.99). To order a copy for £16.14, go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.