Life as the lover of the restless US architect Louis Kahn was fulfilling – but never easy

Not again,” said the great American architect Louis Kahn, when his lover Harriet Pattison told him she was pregnant. He’d had another lover, Anne Tyng, who had had a daughter with him eight years before. It is one of the lines in Pattison’s book that stings. Another comes when she finds that his wife Esther, who was relatively prosperous, was helping to support the precarious finances of Kahn’s studio. It meant that Pattison’s hope that he would leave his wife for her was pushed into a remote and, as it turned out, never achieved future.

Yet Our Days Are Like full Years is not a bitter or angry book. It is a memoir of their times together, moving and heroic (on her part) as well as troubling, built around the letters he sent to her, which she has kept in a Chinese cinnabar box ever since he died in 1974. Their relationship lasted 15 years – “a small portion of time in most lives, and yet measureless in intensity and effect in ours”. Like much of her life, she says, the letters “were unexamined, put off for a later time. But it is a later time now, for I am past 90.”