Last week, I mentioned that attorney Derrick Valkenburg and I would be exploring the natural law origins of affirmative defenses. We also posted some introductory materials to get the ball rolling, including the Wikipedia entry for “affirmative defense” (see here) as well as a laundry list of such legal defenses (here).

First off, however, we want to make a preliminary observation. Some legal defenses are universal — i.e., applicable to any type of claim — such as laches (unreasonable delay in bringing a claim), failure to state a claim, and res judicata, just to name a few. Other defenses, by contrast, are “subject matter specific”, i.e. specifically connected to certain types of law claims or theories of liability. By way of example, the common law defenses of assumption of risk, consent, and waiver are relevant to tort claims (i.e. cases alleging the commission of a wrongful act resulting in an injury to one’s person or property), while the defenses of duress, mistake, and promissory estoppel are relevant to claims alleging a breach of contract.

So, what should we make of this particular distinction? Why are some defenses subject matter specific, while others are universal? Do all defenses nevertheless share the same logical structure, or are there deep differences between specific versus universal defenses? We will take a closer look at these questions in the days ahead …