It is necessary, in order that my plea should be understood, that I should explain what I mean by Christianity; and in the very attempt at this explanation there will, I think, be found strong illustration of the value of unbelief. Christianity in practice may be gathered from its more ancient forms, represented by the Roman Catholic and the Greek Churches, or from the various churches which have grown up in the last few centuries. Each of these churches calls itself Christian. Some of them deny the right of the others to use the word Christian. Some Christian churches treat, or have treated, other Christian churches as heretics or unbelievers. The Roman Catholics and the Protestants in Great Britain and Ireland have in turn been terribly cruel one to the other; and the ferocious laws of the seventeenth and eighteenth centuries, enacted by the English Protestants against English and Irish Papists, are a disgrace to civilisation. These penal laws, enduring longest in Ireland, still bear fruit in much of the political mischief and agrarian crime of to-day. It is only the tolerant indifference of scepticism that, one after the other, has repealed most of the laws directed by the Established Christian Church against Papists and Dissenters, and also against Jews and heretics. Church of England clergymen have in the past gone to great lengths in denouncing nonconformity; and even in the present day an effective sample of such denunciatory bigotry may be found in a sort of orthodox catechism written by the Rev. F. A. Gace, of Great Barling, Essex, the popularity of which is vouched by the fact that it has gone through ten editions. This catechism for little children teaches that "Dissent is a great sin", and that Dissenters "worship God according to their own evil and corrupt imaginations, and not according to his revealed will, and therefore their worship is idolatrous". Church of England Christians and Dissenting Christians, when fraternising amongst themselves, often publicly draw the line at Unitarians, and positively deny that these have any sort of right to call themselves Christians. In the first half of the seventeenth century Quakers were flogged and imprisoned in England as blasphemers; and the early Christian settlers in New England, escaping from the persecution of Old World Christians, showed scant mercy to the followers of Fox and Penn. It is customary, in controversy, for those advocating the claims of Christianity, to include all good done by men in nominally Christian countries as if such good were the result of Christianity, while they contend that the evil which exists prevails in spite of Christianity. I shall try to make out that the ameliorating march of the last few centuries has been initiated by the heretics of each age, though I quite concede that the men and women denounced and persecuted as infidels by the pious of one century, are frequently claimed as saints by the pious of a later generation.