No Stupid Questions: What is a Cause of Action?

What is a “cause of action?” you whisper, so other attorneys won’t hear. Good question. It’s a good question because, like any good legal question, it’s complicated. “Cause of action” is a phrase attorneys use almost every day, at least in their heads, but for which they may have no working definition. We all get along just fine without a definition, for this term and many others, so what’s the big deal?  The importance of this subject is as important as addition and subtraction to calculus, or letters to the English language. It is about the foundation from which law stems.

A place to start, better or worse, is the modern definition. Oran’s Legal Dictionary defines a “cause of action” as “facts sufficient to support a valid lawsuit” or “the legal theory upon which a lawsuit is based.”[i] Easy enough. Let’s pack it up and go home. But wait! I have a whole article left and I am not, nor should you be, satisfied with a two-sentence answer. Unfortunately, it seems like everyone but you and I are satisfied, because in order to find a more robust  definition we’ve got to go way back, all the way back to 19th century lawyer, and pince-nez wearing Morpheus superfan, John Norton Pomeroy. He defined the “cause of action” as follows:

Every judicial action must therefore involve the following elements: a primary right possessed by the plaintiff, and a corresponding primary duty devolving upon the defendant; a delict or wrong done by the defendant which consisted in a breach of such primary right and duty; a remedial right in favor of the plaintiff, and a remedial duty resting on the defendant springing from this delict, and finally the remedy or relief itself.[ii]

The astute among you will notice a distinct familiarity with this definition, like déjà vu or an old friend. Even if you don’t practice tort law, the smell of fear from your torts class likely still lingers. This definition looks much like the definition of negligence, or for purposes of our discussion, the “cause of action” of negligence. That is because negligence holds a special place in the law. A “cause of action” can be statutorily created, like a crime, and while the elements may not be spelled out in the above form, they exist inherently. A person has a duty not to kill people. The General Assembly hardly needs to add it to the code section on homicide.[iii] Negligence, on the other hand, exists in the common law and can be used as a template to capture as many “causes of action” as you can dream up and then some if you’re arguing a duty and right yet to be addressed by the courts.[iv]

Is that it? Well, since you asked, let’s keep going and practice what legal historian S.F.C. Milsom calls “law read backwards.”[v] The history of the law is one of diverse customs wrangled by increasingly centralized institutions and the struggle to maintain that diversity while simultaneously promoting order. There is so much to be said regarding the history of the common law that it would require a book; luckily for you there are plenty out there.[vi] So let’s point to the final development in the common law that led to the “cause of action” as we know it today: the jury trial.

You probably already understand the introduction of the jury trial changed our entire system, but pleadings took on a completely different tone, when their ancient form (called Oral Pleading) met the fallibility of jurymen. In the 12th century, a lawsuit was a formal claim made by the plaintiff and an equally formal denial by the defendant and those claims had to be stated just so and correctly, and most importantly, in Latin. It became prudent when a jury was involved to perhaps let the defendant say a little more. The pervasive belief was that although God could not be misled by the ancient Latin statements of denial, when the decision was put into the hands of a group of fallible men, this meant that perhaps some facts were necessary to be put forth.

You can then surmise that the plaintiff would of course want to say something about that denial, meaning the formal Latin pleading had to be modified to introduce facts as well to answer the defendant’s claims. Over time the system of Oral Pleadings became too unwieldy. The new pleading system developed to be completed pre-trial, before the time of Oral Pleadings, and the claim would be made. If there was an issue with law, it was decided by the court, if there was a dispute as to facts it would be handled at nisi prius, or in the trial court hearing facts.

And from this the modern “cause of action” and pleading system arose. This was a slow development over hundreds of years, with turn after turn running through different regents, different court structures, and new developments on top of them. It was an effort to create something more efficient, more practical, and more flexible in the face of humanity’s fallibility and the realization that we cannot boil every dispute down to a Latin phrase. Eventually, after all those individual’s work and efforts, sergeants at arms, barristers, apprentices, and individuals attempting to capture each case’s own twists, we are left with “facts sufficient to support a valid lawsuit.”

So the next time you want to ask a legal question you believe is stupid, just remember what a “cause of action” is, because your question may not be as stupid as you think.


[i] Cause of action, Oran’s Dictionary of the Law (4th ed. 2007).

[ii] John N. Pomeroy, Code Remedies, § 347 (4th ed. 1904).

[iii] If you’re feeling particularly philosophical, a question exists in the study of meta-ethics regarding whether we have any rights at all and, if we do, where they come from. This is referred to as rights-based ethics. I would suggest looking up the works of Jeremy Bentham. Most philosophers find rights to be difficult to pin down or as Bentham calls them, “nonsense upon stilts.”

[iv] This is certainly not a statement of your ability to win that argument, nor am I encouraging legal exhibitionism. Then again, it’s your life.

[v] S.F.C. Milsom, Historical Foundations of the Common Law ix (1969). This work serves as the primary reference for the historical discussion in the remainder of this article.

[vi] I recommend Milsom’s work and The Common Legal Past of Europe: 1000-1800 by Manlio Bellomo and translated by Lydia G. Cochrane.

About the Author

mattfinley-snimgeditMatthew G. Finley is a former prosecutor, now practicing personal injury and worker’s compensation in Tidewater Virginia. When he has trouble sleeping he partakes in the occasional reading of legal history.