Not least, in that it shows how quickly radicals can be forgotten. No one I have asked can recall who Hicks was. Yet by his death, in 1919, he was far and away the most politically advanced bishop.
Hicks did not go to a theological college, so his education was identical with that of his lay peers. His language and imagery were easily understood by his audiences. Hicks's political and social philosophy came directly from his view of the Gospels. That he had the chance to influence the national debate stemmed, in part, from his fortuitously close association with the legendary Manchester Guardian editor, CP Scott, who, like Hicks, was interested in forming a new radical alliance with Lloyd George at its head. But Hicks's position also owed much to his years of hard work in one of the country's poorest parishes.
In his first appointment, to a rural parish, Hicks began developing out of an evangelical background towards the role of a leading churchman with a deep concern for social reform. But most of his ministry was in the north, in Salford and Manchester. His politics, as well as his churchmanship, was based squarely on the political experience of ministering to the poor.
Hicks was politically astute. Sometimes he saw the importance of operating through church groups; on other occasions he worked through secular organisations. The Christian Social Union is a good example of his church endeavour. This brilliant little pressure group, a kind of hybrid Shelter/CPAG of its day, made the most profound impact. It ranks as the most effective Christian Socialist organisation to have operated in this country.
On temperance, Hicks saw the advantage of allying with a secular campaign. He was strongly in favour of the local option, where people decided their own drink laws. The local approach to solving national issues is significant. He believed that only by building support from the bottom could radical politics take root.
More generally, Hicks was wary of too fast an implementation of socialism. His objection was that socialism required too high a degree of social conscience in ordinary people to be launched unilaterally on an unregenerate world. The history of the 20th century would have been profoundly different if his wisdom had won the day.
It was the range of Hicks's radicalism which Conservatives spun as a sign of instability. Archbishop Davidson, frenetically lobbying prime minister Asquith against Hicks's appointment as a bishop, labelled him faddish - as if someone with a comprehensive programme was in some way insane. The evidence of Davidson's covert lobbying against Hicks, all based on hearsay, is a welcome reminder of the value of a state input into senior Church appointments. Asquith finally won by appointing Hicks Bishop of Lincoln, in a similar battle to the one Tony Blair had recently over the appointment of a Bishop of Liverpool.
Hicks never felt part of the in-crowd. But he was fearless - in helping, for example, to form an early branch of the Labour Party in his diocese. Which bishop would do that today! This book is the first study of how a radical liberal churchman moved towards Labour. His career shows that traditional history's concentration on the Oxford-London axis is a poor guide to what was happening in the rest of the country. It shows, too, how unrepresentative is the normal obsession with Victorian and Edwardian sectarianism.
It also emphasises that the political-religious debate was not just a series of clashes between Conservatives and Christian Socialists. And it shows how someone with talent could ride the two wild horses of the century - biblical scholarship and the development of a middle-class conscience - for the benefit of Church and state alike.
The reviewer is Labour MP for Birkenhead and former minister for welfare reform