Motus Unitarianus, quamquam Unitarianus primum non appellatus, paene simul coepit in Polonia-Lithuania et Transylvania medio saeculo sexto decimo, inter cuius assectatores fuerunt aliqui Italici.[11][12] In Anglia, prima ecclesia unitariana anno 1774 in Via Essex Londinii constituta est, ubi praesidium Britannicum hodiernum iam patet.[13] Prima sollemnis fidei Unitarianae acceptio per omnem congregationem in America in Cappella RegisBostoniae facta est, unde Iacobus Freeman doctrinam unitarianam anno 1784 docere coepit, et, rector rite creatus, Librum Precum secundum doctrinas Unitarianas anno 1786 retractavit.[14]
Iosephus Priestley, unus ex conditoribus motus Unitariani, Unitarianismum definivit fidem Christianitatis primae, antequam corruptiones coeperant. Inter has corruptiones, non solum doctrinam Trinitatis, sed etiam alias doctrinas orthodoxas et usus perscripsit (Wilbur 1952:302–303).
Ex catechismo Ecclesiae Unitarianae Hungaricae in Transylvanian Romania: "Unitarians do not teach original sin. We do not believe that through the sin of the first human couple we all became corrupted. It would contradict the love and justice of God to attribute to us the sin of others, because sin is one's own personal action." Conversus ex Hungarica a Gyorgy Andrasi, The Unitarian Universalist Christian 49.3–4 (1994): 7:107.
In historia Unitarianorum, David Robinson scribit: "At their inception, both Unitarians and Universalists shared a common theological enemy: Calvinism": they "consistently attacked Calvinism on the related issues of original sin and election to salvation, doctrines that in their view undermined human moral exertion," in The Unitarians and the Universalists (Greenwood Press, 1985), 3, 17.
"Although considering it, on the whole, an inspired book, Unitarians also regard the Bible as coming not only from God, but also from humans; . . . Unitarians therefore do not believe in the infallibility of the Bible, as some other Christians do." D. Miano, An Explanation of Unitarian Christianity (AUC, 2003, 2007).
J. Gordon Melton, ed., Encyclopedia of American Religions (ed. 8a) "Brought together in this chapter as the 'liberal' family of churches and 'religious' organizations are those groups that have challenged the orthodox Christian dominance of Western religious life: Unitarianism, universalism, and infidelism" (p. 611).
James Hastings, Encyclopaedia of Religion and Ethics: Algonquins-Art, 785–2001: "The first Unitarians were Italians, and the majority took refuge in Poland, where the laxity of the laws and the independence of the nobility secured for them a toleration which would have been denied to their views in other countries."
Hans Joachim Hillerbrand, ed., The Encyclopedia of Protestantism: "The so-called Golden Age of Unitarianism in Transylvania (1540–1571) resulted in a rich production of works both in Hungarian and Latin" (2004).
Erwin Fahlbusch, The Encyclopedia of Christianity (2008), vol. 5, p. 603: "Lindsey attempted but failed to gain legal relief for Anglican Unitarians, so in 1774 he opened his own distinctly Unitarian church on Essex Street, London, where today's British Unitarian headquarters are still located."
American Unitarianism: or, A Brief history of "The progress and State of the Unitarian Churches in America, third edition, 1815 "So early as the year 1786, Dr. Freeman had persuaded his church to adopt a liturgy, which the Rev. . . . Thus much for the history of Unitarianism at the Stone Chapel. "
Allen, Joseph Henry. 1882. Our Liberal Movement in Theology. Bostoniae.
Allen, Joseph Henry. 1897. Sequel to our Liberal Movement. Bostoniae.
Buzzard, Anthony F., et Charles F. Hunting. 1998. The Doctrine of the Trinity: Christianity's Self-Inflicted Wound. Lanham Terrae Mariae: International Scholars Publications. ISBN 1-57309-309-2.
Chadwick, John White. 1894. Old and New Unitarian Belief. Bostoniae.
Cooke, George Willis. 1902. Unitarianism in America: a History of its Origin and Development. Bostoniae.
Hewett, Austin Phillip. 1955. An Unfettered Faith: the Religion of a Unitarian. Londinii: Lindsey Press.
Howe, Charles A. 1997. For Faith and Freedom: A Short History of Unitarianism in Europe. Bostoniae: Skinner House Books. ISBN 1558963596.
Lloyd, Walter. 1899. The Story of Protestant Dissent and English Unitarianism. Londinii: P. Green.
Navas, Patrick. 2007. Divine Truth or Human Tradition: A Reconsideration of the Roman Catholic-Protestant Doctrine of the Trinity in Light of the Hebrew and Christian Scriptures. Bloomington Indianae. ISBN 1-4259-4832-4.