As Doris Lessing discusses in her own introduction (new for this edition), her best-known and best-selling novel has been viewed as being "about" various things: the battle of the sexes and man's inhumanity to woman; mental health; the difficulties facing left-wing politics following the failure and collapse of communism. As she herself points out, there is a definite irony in this, given that her central theme and premise was the need to see things as a whole and avoid compartmentalising different aspects of our lives (love life, family life, political life, work life etc. etc.). This remains a startling idea: what Lessing is essentially saying is that it is just this sort of compartmentalising that allows an otherwise kind character to be a shameless racist (there is a prominent example in the Black Notebook), or an operative of a totalitarian regime to commit acts of genocide then go home to a peaceful family dinner.
At the novel's opening, the life of Lessing's central character - (ex-)novelist Anna Wulf - seems hopelessly fragmented. Afflicted by writer's block, Anna pours the narrative of the various traumas of her life into four quite separate compartments: the Black Notebook relates to her "work life" as a writer; the Red Notebook her "political life" as a lapsed and disillusioned member of the British Communist party; the Yellow Notebook her (lightly fictionalised) love life; and the Blue Notebook her everyday existence. In all four areas, things grow increasingly desperate until Anna's mental health seems in serious question. However, it is only after what amounts to a "breakdown" followed by re-synthesis of her life as a whole in the eponymous Golden Notebook that Anna can really achieve mental and moral wellbeing.
It is a startlingly honest book, particularly for its time, and it is easy to empathise with Anna's plight. Lessing writes beautifully (particularly in the dark-hued and intensely nostalgic African sections of the Black Notebook), and throws off ideas and philosophical digressions like fireworks.
The book has undoubtedly dated a little, particularly in the ever-thorny area of sexuality and gender politics. As noted by another reviewer below, Anna's attitude to her gay lodgers is a tad dubious: it's fair enough to criticise them for being bitchy and misogynistic (they are!), but surely not for failing to be "Real Men"? Similarly, Anna not infrequently expresses (via her fictional alter ego in the Yellow Notebook) a somewhat unreconstructed craving to be sexually "Swept Away" by a "Real Man" (whatever one of those is) - while she clearly doesn't mean some sort of macho schmuck, this does jar a little nowadays. In part this is connected to Lessing's fascination at the time with a rather mystical version of Jungian psychoanalytical theory, with its ideas of "animus and anima": this was very trendy at the time (it crops up in the writing of Robertson Davies and Iris Murdoch, for instance) but seems less relevant nowadays. It is also worth remembering that Lessing was writing in the very early Sixties, well before the days of Shere Hite and Nancy Friday, and that her views on sex and sexuality were in fact very progressive and unexpectedly honest for the book's era. The novel's central theme (the need to live life as a whole) remains startling and compelling, and overall there is no question that this is a five-star read.