Essay: The Unconstitutionality of Slavery

Overview
Lysander Spooner mounts a systematic legal and moral attack on the idea that the U.S. Constitution authorizes slavery. He rejects the claim that the document either expressly or implicitly grants a right to hold human beings as property, and he insists that the Constitution's language, structure, and founding principles are inconsistent with the institution of chattel slavery. Spooner frames his argument both as a textual, forensic reading of the Constitution and as an appeal to the natural-rights principles that informed American political thought.
Spooner's tone is both juridical and passionate. He treats pro-slavery constitutional interpretations as strained readings that require importing assumptions foreign to the text and to the spirit of republican government. Throughout, he challenges the legal theories of leading pro-slavery thinkers and stresses that law must protect individual liberty rather than legitimate domination.

Method and Core Claim
Spooner begins with a methodological commitment to close textual analysis combined with natural-law reasoning. He argues that the Constitution's legitimacy rests on consent and that no clause may be read as authorizing the moral and legal atrocity of owning other persons. Because the Constitution nowhere uses the word "slave" to create an instrument of domestic bondage, Spooner treats any interpretation asserting an affirmative constitutional sanction of slavery as illegitimate.
His core claim is simple and forceful: the Constitution does not empower government officials to make human beings property, nor does it shield such ownership from challenge. Where the document refers to persons, it does so in terms that presuppose personhood and rights, not proprietary status, and any clause that seems to touch on slavery must be read in harmony with the overarching commitment to liberty.

Analysis of Key Clauses
Spooner closely examines clauses often cited by pro-slavery advocates, notably the Fugitive Slave Clause, the Three-Fifths Clause, and the Articles concerning federal powers. He argues that the Fugitive Slave provision, properly understood, required only cooperation in returning individuals whom state law had already declared "held to service," and it did not create a federal power to invent or perpetuate slavery where it did not legally exist. He insists that personal liberty cannot be nullified by ambiguous phraseology or by reading property rights into silence.
Regarding other clauses, Spooner stresses that the Constitution's guarantees, such as due process and trial protections inherent in republican institutions, are inconsistent with the summary dominion required by chattel slavery. He treats pro-slavery readings as attempts to smuggle private property metaphysics into a public charter designed to limit governmental coercion.

Refutation of Pro-Slavery Doctrines
Spooner takes aim at the intellectual scaffolding of pro-slavery constitutionalism, exposing logical flaws and historical misreadings. He challenges claims that the founders intended to accept slavery as a constitutional norm, pointing out that many framers used careful language about persons and rights and that the political compromises of the founding do not equate to an endorsement of perpetual bondage. He also rejects notions that state enactments could retroactively convert free persons into property without violating basic rights.
Spooner emphasizes that legal arguments must not be decoupled from moral premises: to accept slavery as constitutional is to abandon the principles of natural liberty that the Revolution professed. He portrays pro-slavery juristic contortions as inconsistent with the ordinary meaning of the constitutional text and the ethical foundations of law.

Conclusion and Influence
Spooner concludes that slavery lacks constitutional protection and that slaves, as persons, retain natural rights that the national compact does not extinguish. His essay supplies abolitionists with a rigorous, law-centered rebuttal to claims that the federal charter legitimized bondage. By combining close textual exegesis with a bold appeal to natural rights, the argument reorients the constitutional debate and underscores the possibility of using the Constitution to resist, rather than justify, slavery.
Though controversial in its time, Spooner's analysis became an influential strand of abolitionist constitutionalism, offering moral and legal ammunition to those who sought to interpret the nation's founding instruments as instruments of liberty rather than instruments of oppression.