Franklin's hatred of negro slavery was conditioned by more than his humanitarian bias. It may be seen that his indictments of black cargoes were the resultant of an interplay of his convictions that economically slavery was enervating and dear and of his abstract sense of religious and ethical justice. One should not minimize, however, his distrust of slavery on other than economic bases. He was acutely influenced by the Quakers of his colony who, like gadflies, were stinging slaveholders to an awareness of their blood traffic, and by the rise of English humanitarianism. In his youth he had published (first edition, 1729; second, 1730), with no little danger to himself and his business, Ralph Sandiford's _A Brief Examination of the Practice of the Times_, an Amos-like vituperative attack on the "unrighteous Gain" of slaveholding. He also published works of Benjamin Lay and John Woolman.[i-180] Friend of Anthony Benezet, Benjamin Rush, Fothergill, and Granville Sharp, and after 1760 a member of Dr. Bray's Associates, he lent his voice and pen to denouncing slavery on religious and ethical grounds; and in England, after the James Sommersett trial (1772), he "began to agitate for parliamentary action" toward the abolishing of slavery in all parts of the British Empire.[i-181] Following the Sommersett verdict, Franklin contributed a brief article to the _London Chronicle_ (June 18-20, 1772) in which he denounced the "constant butchery of the human species by this pestilential detestable traffic in the bodies and souls of men."[i-182] Losing his temperamental urbanity when observing "the diabolical Commerce,"[i-183] "the abominable African Trade," he recollects approvingly that a certain French moralist[i-184] could "not look on a piece of sugar without conceiving it stained with spots of human blood!"[i-185] Conditioned by Quakerism, by his deism, which suggested that "the most acceptable Service we render him [God] is doing good to his other Children," and by the eighteenth century's growing repugnance toward suffering and pain,[i-186] Franklin (although he took little part in legislating against slavery in Pennsylvania) became through his writing a model to be imitated, especially in France, by a people more intent on becoming humane than saintly. His letter to Anthony Benezet (London, July 14, 1773), however, clearly indicates that for economic, as well as humanitarian reasons, he had sought freedom for slaves: I am glad to hear that such humane Sentiments prevail so much more generally than heretofore, that there is Reason to hope our Colonies may in time get clear of a Practice that disgraces them, and, without producing any equivalent Benefit, is dangerous to their very Existence.[i-187]