I think that one of our most important tasks is to convince others that there's nothing to fear in difference; that difference, in fact, is one of the healthiest and most invigorating of human characteristics without which life would become meaningless. Here lies the power of the liberal way: not in making the whole world Unitarian, but in helping ourselves and others to see some of the possibilities inherent in viewpoints other than one's own; in encouraging the free interchange of ideas; in welcoming fresh approaches to the problems of life; in urging the fullest, most vigorous use of critical self-examination.
Adlai Stevenson, as quoted in Challenge of a Liberal Faith (1988), by George N. Marshall, Ch. 3 : A Contemporary Religion, p. 34
By the mid-century many of the younger educated ministers prided themselves on their broad-minded rational theology. The Calvinist self-righteousness of the persecuted sect was left behind, and they gravitated through Arian and Socinian "heresy" towards Unitarianism. From Unitarianism it was only a further step to Deism, although few took this step until the 1790s; and even fewer in the second half of the 18th century wished or dared to make a public avowal of scepticism—in 1763 the seventy-year-old schoolmaster, Peter Annet, was imprisoned and stocked for translating Voltaire and for publishing "free-thinking" tracts in popular form, while shortly afterwards the sceptical Robin Hood debating society was closed down. It was from Socinian or Unitarian positions that liberal principles were argued: the famous figures are Dr. Price, whose Observations on Civil Liberty (1776) at the time of the American War achieved the remarkable sale of 60,000 within a few months, and who lived to enrage Burke by his sermon in welcome to the French Revolution; Dr. Priestley himself; and a score of lesser figures, several of whom— Thomas Cooper of Bolton and William Frend of Cambridge— took an active part in the reform agitation of the 1790s.
E. P. Thompson, The Making of the English Working Class (1963), p. 27