Book of a Lifetime: What Maisie Knew, By Henry James

Greener than Maisie, when I first heard What Maisie Knew being praised as a child I assumed that the last two words of the title were a French word – Maisyneux, like Mollyneux – and had no idea the book was about a girl. When I did first read it in my mid-teens I instantly felt the smash of Maisie's world on my mind and heart.

I was drawn straight away to a preoccupation in the book that I would later locate in much of Henry James's writing: the theme of how to live fully in the world, without taking on any of the taint that the word "worldly" carries. When you read with a pet idea in mind you are liable to see it everywhere, but when I went to university later and found a brilliant teacher – Barbara Everett – who was as interested in this as I was, or seemed to be, it felt very luxurious.

Grappling with James's preface as a teenager, I was very taken with his notion that "the muddled state too is one of the very sharpest of the realities". This seemed to me to convey something very acute about childhood and its intensity. I had wondered as a child whether most people experience their strongest feelings before the age of ten.

In What Maisie Knew, Maisie's girlish attempts to make sense of things, the lucky guesses that lead to false impressions, the innocent mistakes that sometimes catch at greater truths, and the deepening of character that comes with experience, are all conveyed with both verve and delicacy. There are two reasons that this book about a girl growing up in intolerable circumstances isn't more terrible than one can bear.

Much has been made of the fact that James gives us the "muddle" with such symmetry, as if it were almost a formal dance: the separation of the parents, the new pairings, the changes of partners, the Kensington Gardens incidents that are mirrored, the father's yellow-and-black shoes patent set against the stepfather's dove-grey gloves with black stitching. All these things lend a sort of wit and pattern to the proceedings that spare one slightly from their horror.

However, it is Maisie herself who makes this novel a delight to return to regularly. James called her his "interesting small mortal" and, while this hints at her vulnerability, it tells next to nothing of her charm and nerve in the face of betrayal, which are heroic. Her unfailing character, her lack of misgivings, her indulgences, her capacity for joy and above all her faith in the idea of faith itself are wildly attractive on the page. I love her.

Susie Boyt's new novel is 'The Small Hours' (Virago)