by Andrew Flake

This week, we hold up for praise…the inference. Unassuming and hardworking, inferences reward more careful attention than we give them. The careful reader will recall, for example, that last week’s Eleventh Circuit case turned on an inference — whether it was proper to draw, and therefore whether summary judgment was proper or not. Inferences can determine of our trials as well.

Let’s start with meaning. We refer so much to inferences in legal analysis that I think sometimes we lose the nuances. An inference is defined as “a conclusion or opinion that is formed because of known facts or evidence.” We’ve had a rainy stretch of days in Atlanta. If we look outside, we know that the pavement is wet. We would know that leaves and sticks are scattered around and that the sky is grey. But if we saw all of that, and it weren’t raining at the moment, we would infer that it had rained recently. To infer something, in this context, is to draw a conclusion based on a number of specific facts.

That particular inference is also an example of “inductive reasoning,” which is similar to what scientist do in a more rigorous way, collecting data and observations about the world, like the flight pattern of birds, and developing a generalized theory.

How strong an inductive conclusion is can be in the eye of the beholder or, in the trial context, in the eyes of our jury members. In my example, the inference that it had rained is a pretty sound one. Might someone have come by hosed down the street, scattering debris around? Pretty unlikely. Of course, if we walked out and looked around, and noticed that everything else outside of a 25-yard radius was dry and tranquil, we might wonder.

“Deductive reasoning,” on the other hand, is taking facts that we know, and drawing conclusions that are not just probable, but must follow logically. A “process of elimination,” ruling out every possibility but one, is an example of deductive reasoning — and how literary detectives like Sherlock Holmes, patiently educating Dr. Watson, or Hercule Poirot, addressing a rapt roomful of suspects, famously unravel the crime.

The syllogism — a major premise or legal rule, a minor premise drawn from the evidence, and a conclusion — is another example of deductive reasoning, and one that is fundamental to how we make legal arguments. “A verbal agreement to sell property is not enforceable. The agreement Jane made to sell was over the phone; Jane therefore does not have an enforceable agreement.”

So not every inference is created equally. Some are logically compelled; some are just compelling. In a future post, I’ll look at some additional examples, including ways we can deploy them to advantage in closing argument.