Throughout his career Klein entertained high, perhaps impossibly high, ambitions for his poetry. Poetry was not true poetry unless it engaged some great theme; and Klein’s career as a poet is largely the record of a continuous inner struggle, through periods of silence as well as ones of intense productivity, to define and redefine such a theme, and to develop the means – emotional, intellectual, and artistic – to do it justice. It is a struggle which culminates in the great achievements of his maturity, and, then, in the bleak silence of his final years.

The essence of Klein’s theme...