Martin Luther King Jr. Stands Firmly on the Shoulders of Augustine and Aquinas

“Any law that uplifts human personality is just. Any law that degrades human personality is unjust.”

Rev. Martin Luther King speaks at a press conference on Nov. 6, 1964
Rev. Martin Luther King speaks at a press conference on Nov. 6, 1964 (photo: Dick DeMarsico / New York World Telegram and Sun / Wikimedia Commons / Public Domain)

Rev. Martin Luther King, Jr., leader of the nonviolent Civil Rights Movement of the 1950s and '60s, helped Americans to understand that while obedience to the law is important, one is not required to obey an unjust law. In his “Letter from a Birmingham Jail” on April 16, 1963, he drew on the teaching of St. Thomas Aquinas to explain the difference between just and unjust laws:

One may well ask: “How can you advocate breaking some laws and obeying others?” The answer lies in the fact that there are two types of laws: just and unjust. I would be the first to advocate obeying just laws. One has not only a legal but a moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws. I would agree with St. Augustine that “an unjust law is no law at all.”

Now, what is the difference between the two? How does one determine whether a law is just or unjust? A just law is a manmade code that squares with the moral law or the law of God. An unjust law is a code that is out of harmony with the moral law. To put it in the terms of St. Thomas Aquinas: An unjust law is a human law that is not rooted in eternal law and natural law. Any law that uplifts human personality is just. Any law that degrades human personality is unjust.

Martin Luther King, Jr.
“Letter from a Birmingham Jail”
April 16, 1963


Was Reverend Martin Luther King, Jr. a Thomist?

Well, yes. Thomas Aquinas, a 13th-century Catholic philosopher and theologian, argued that laws bind the conscience—that is, obligate one to obey—only when the laws conform to “eternal law.”

St. Thomas Aquinas, in the Summa Theologiae, argued that we must obey laws only

  • when they conform to “eternal law,” the law of God, and
  • when that eternal law is self-evident—is exhibited in the universal principles of practical reason (what we call “natural law”).

To be just, a law must be good as to:

  1. its end: it must be ordered to the common good;
  2. its author: it must not exceed the jurisdiction of the one who imposes it;
  3. its form: it must not place disproportionate burdens on any of the subjects involved.

Thomas Aquinas taught that a law that is unjust in any of these ways, and that it does not impose any obligation; and that is, a law ceases to have binding force if any of these is true:

  1. the law is not ordered to the common good, but merely to the private good of those who impose it;
  2. it exceeds the authority of those who impose it; or
  3. it places disproportionate burdens on any of the people in the community.

Aquinas explained at an act that does any of these things is more like an act of violence than like a law. It may share some features of a just law, but it is not a law in precisely the same sense.

So Aquinas teaches, as does St. Augustine before him, that just law is no law at all. The only way in which an unjust law may obligate is indirectly—when it is clear that disobeying it would lead to evils worse than obeying it.


The Violence of Corruption

Aquinas’ third argument against an unjust law , drawn from his 1963 “Letter From a Birmingham Jail”. In it, he teaches:

that human laws do not obligate when they bring injury and loss of character on human beings—when they oppress the poor and humble. Oppressive laws, Aquinas taught, are perversions of law, acts of violence; and no one need feel guilty about disobeying an unjust law.

So Martin Luther King, Jr. is, in fact, a Thomist. In his famed Letter from a Birmingham Jail, he argued that a nonviolent campaign follows four stages:

  1. collection of facts to determine whether injustice actually exists;
  2. negotiation in order to resolve the matter peacefully;
  3. self-purification, in which there is careful preparation for nonviolent direct action;
  4. direct action through nonviolent means.

Were the civil rights protestors in 1963 offending God when they broke the law and sat at a Woolworth's Lunch Counter in Greensboro, North Carolina? Was Rosa Parks sinning when she refused to give up her seat on the bus to a white person, sparking the Montgomery Bus Protest? No, said Dr. King; and to prove that, he cited Aquinas’ argument. “Any law that degrades human personality,” said King, “is unjust. All segregation statutes are unjust because segregation distorts the soul and damages the personality.”

What King did was skillfully apply Aquinas’ Third Objection—teaching that the South’s segregation laws were unjust because of the moral and physical injury they induced.

Dr. Alveda King, niece of Dr. Martin Luther King, Jr., continues his legacy of peaceful protest today—reminding us that her uncle was pro-life. Had King lived to see the dire consequences of Roe v. Wade, the innocent children torn apart in the womb, he would have applied Aquinas’ logic to this most pressing societal ill.