John Henry Wigmore

The why.

Why is the Anglo-American legal tradition so deeply terrified of out-of-court statements? Why is the system designed to block a witness from just sitting on the stand and saying, "Well, my friend John told me he saw the defendant rob the bank"?

It all comes down to human fallibility.

John Henry Wigmore, who is essentially the foundational architect of modern American evidence scholarship, identified what he called the four testimonial infirmities.

Whenever a human being communicates information, there are four inherent risks or, you know, defects that can fatally distort the truth.

Let's walk through these using a hypothetical for the listener.

Let's say we have a witness, Sarah, who claims she saw a car accident at dusk, and she tells her friend Mark about it.

Later, Mark is on the witness stand, trying to testify about what Sarah said.