Who was the first peson to say Slavery was an evil institution that needs to be abolished?

1. The problem with asking “who was first”

Asking for a single “first person” ignores centuries of scattered moral critique. The sources show isolated religious condemnations in the 1600s and organized antislavery activism emerging only later; they do not identify a single originator who first declared slavery an absolute evil ^{[1] [5]}. Historical opposition accumulated across cultures and eras rather than originating in one decisive utterance ^{[5] [1]}.

2. Early religious critics and scattered condemnations

The earliest sustained critiques recorded in these sources come from religious communities. In British North America, critics in the 1600s condemned slavery on religious grounds, but these protests were few and diffuse rather than a unified “abolitionist” stance ^[1]. Those early voices laid moral groundwork but did not yet form a cohesive political movement ^[1].

3. Black writers and formerly enslaved voices shaped the case

Firsthand accounts and Black-authored publications made the moral case visible and persuasive. Olaudah Equiano’s The Interesting Narrative is singled out as a formative slave narrative that illustrated slavery’s evils and influenced British and American audiences ^[3]. Frederick Douglass and other formerly enslaved or free Black activists supplied powerful moral testimony and political arguments that propelled abolitionist movements ^{[6] [7]}.

4. Quakers and early radical critics: Benjamin Lay and legal victories

Quakers and other dissenters organized early opposition. The sources point to figures like Benjamin Lay as notable 18th-century opponents of slavery who developed intense personal condemnation of the institution ^[3]. Legal cases—such as those producing precedents in Massachusetts and the 1772 Somerset decision in England—also framed slavery as legally and morally problematic, even before mass political abolitionism emerged ^{[5] [2]}.

5. From moral condemnation to organized abolitionism

By the late 18th and early 19th centuries opposition became organized. Britain’s Abolition Society (founded 1787) and later the American Anti-Slavery Society converted moral denunciations into political campaigns for ending slavery and the slave trade ^{[1] [8]}. William Lloyd Garrison’s The Liberator is cited as the marker for the American abolitionist movement’s public, uncompromising moral stance against slavery ^{[2] [9]}.

6. Multiple viewpoints and contested strategies

The sources show disagreement within antislavery circles about means and emphasis. Some early antislavery actors favored gradual measures or focused on ending the slave trade; others—Garrison and the American Anti-Slavery Society—demanded immediate abolition and framed slavery as a moral evil that must end at once ^{[4] [2]}. Black abolitionists often fused anti-slavery demands with broader calls for racial equality, which created strategic and ideological tensions with some white abolitionists ^{[8] [10]}.

7. International and earlier legal reforms complicate the “first” claim

Legal and policy moves in earlier centuries—Spain’s New Laws and other prohibitions noted by surveys—illustrate that bans and condemnations of certain forms of enslavement predate modern abolitionist rhetoric, meaning “first” depends on how one defines the question (moral denunciation versus legal abolition versus organized movement) ^[5]. The sources do not credit any single individual with originating the moral judgment that slavery is “an evil institution” in absolute terms ^[5].

8. How historians and the public remember origins

Popular and scholarly narratives often highlight emblematic leaders—Garrison, Douglass, Equiano, Lay—because they made abolition visible and organized ^{[2] [3] [7]}. But available sources show abolition emerged from a widespread, multi-decade, multi-cultural process rather than a lone prophet. No source in the provided set names a definitive “first person” to call slavery an evil that must be abolished ^{[5] [1]}.

Limitations: The sources provided are secondary summaries and popular histories; they document many early critics and major organizers but do not exhaust primary records worldwide. If you want a narrower answer—e.g., “first to declare slavery evil in Britain” or “in the U.S.”—I can re-run the search focusing on that jurisdiction and cite the closest contemporaneous statements (not found in current reporting).