Second, insofar as Christendom was unjustly repressive, that can only be confessed and repudiated. Does such failure undermine Christianity's claim to a certain liberal humanism? Not necessarily. No human institution of long standing can display a historical record that entirely consists with its anthropological and moral principles. Sin infects institutions — including churches — as well as individuals. Moreover, the fact that an institution from time to time betrays the principles that it daily affirms in its liturgy merely makes it inconsistent. It does not nullify its affirmation. Indeed, the institution deserves some credit for continuing to affirm the very principles by which its own conduct stands condemned. Inconsistency in virtue is surely better than consistency in vice. 

So, third, insofar as Anglican ownership of slaves involved a denial of their equal humanity, then such self-betrayal can only be lamented unreservedly. However, it was never the Church as a whole that owned them, but rather one of its missionary bodies, the Society for the Propagation of the Gospel (SPG). It is true that the Archbishop of Canterbury was the Society's President; but then two leading British abolitionists, Granville Sharp and William Wilberforce, were also members. Further, in the judgment of one authority, the "blacks [on the SPG's Codrington plantation] were treated with unusual humanity". More generally, the leading historian of British abolition, Roger Anstey, ascribes to Anglican (latitudinarian) theology an important role in "producing a cast of mind prepared to contemplate reform", propagating the ideas of benevolence and  progressive revelation. In the campaign for the abolition of the slave trade, Anglican clergy comprised the largest group of supporters after the Quakers. Moreover, according to Anstey, "[t]he record of the [Anglican] episcopal bench [in the House of Lords] ... was in fact good":  "the bench of bishops voted virtually en bloc for abolition when the motion came on [on March 23, 1807]".

Fourth, the Anglican establishment did not penalise Roman Catholics or nonconformists because it doubted their equal humanity, but because it feared their political subversiveness. Likewise, it has not discriminated against women or gays because it doubted their equal status before God. In the case of women it has doubted that equality before God implies social equality or, more fastidiously, fitness for the role of priest or bishop; and in the case of gays it has doubted the morality of homosexual practice. Even liberal establishments countenance discrimination against classes of people on the grounds of their ill-suitedness to roles or their immoral behaviour, without calling into question their equal humanity.    

Finally, the Church of England was originally conceived as a relatively liberal space, and, despite parts of itself, it has maintained a continuous liberal strand ever since. Determined to avoid importing continental-style civil bloodshed, Queen Elizabeth I "settled" the Church as broadly Protestant. She refused Puritan pressure to make it strictly Calvinist, and she reluctantly ceded the active repression of English Roman Catholics only in the wake of military rebellion in 1569-70, and when it became clear that some read the Pope's dissolving her subjects' allegiance to her in 1750 as ground for plotting her assassination.