Final answer:
William Penn may have reconciled his acceptance of slavery with his humanitarian values by mentally separating his religious and social ideals from the economic realities of the time. He was immersed in a society where slave ownership was common, including among Quakers, though prominent voices within the community eventually led the calls for abolition. The complexities of idealism and pragmatism combined with societal norms likely influenced his stance.
Step-by-step explanation:
William Penn, the founder of the Pennsylvania colony and a prominent member of the Quaker community, could reconcile his humanitarian beliefs with the chattel slavery prevailing in the colonies through a complex web of social, religious, and economic rationalizations, despite the inherent contradictions.
Penn's vision for a 'holy experiment' with religious tolerance and his establishment of friendly relations with native peoples, as well as his status as an elite who never fully abandoned his wealth, might have influenced his capacity to overlook the brutality of slavery.
Some Quakers, including Penn, owned slaves, yet paradoxically, important voices from within the Quaker community, such as John Woolman and Anthony Benezet, were speaking against the practice, calling for abolition and the emancipation of slaves.
Furthermore, these sentiments extended beyond the Quakers, as others like James Otis and Arthur Lee linked the cause of independence with the cause of emancipation, exemplifying the tension between aspirations for universal liberty and the practice of slavery.
By the late 18th century, movements like the Pennsylvania Abolition Society began forming, indicating a shift in perspectives towards a more universal application of freedom, reflecting the ideals of the American Revolution.