When I was a first-year law student at Duke many years ago, my Civil Procedure professor was the delightfully named J. Francis Paschal. Professor Paschal seemed to like to portray himself as a bit of a good ol’ boy, with a protruding gut, truly dreadful sports jackets, hair slicked and parted just off-center, and a drawl as thick as molasses on a cold day (if not nearly so sweet). That image could not mask a keen mind and a sharp wit. Nor did it hide his erudition — in addition to his credentials in the law, Professor Paschal had a Princeton Ph.D. too.
The good professor led his classes using the Socratic conventions of the day. A student was called upon to answer a series of penetrating and perplexing questions supposedly designed to ferret out the nuances of some legal principle or another but which, in reality, served to demonstrate to a class full of bright and full-of-themselves college graduates that they were out of the minors and into the intellectual big leagues. If we were going to compete at that level, we needed to up our collective game considerably.
One day fairly early in the first semester Professor Paschal called on a woman in the row ahead of me (who I shall kindly refer to — using a pseudonym since she is now a Deputy Attorney General — as “Frieda Clancy”) and asked a typically impossible question. SInce Frieda was a friend, I happened to know that her extremely difficult predicament was actually utterly impossible because she was not prepared for class. In fact, it wasn’t just that she wasn’t fully prepared (meaning that she had read the required case, all the cases cited therein, the case comments, casebook notes and citations, relevent hornbook and law review materials and anything else we could think of that might be relevant). She wasn’t prepared at all. She hadn’t even read the case at issue.
The photograph above, taken at the Brooklyn waterfront on the afternoon of September 11, 2001 by German photographer Thomas Hoepker, is now one of the iconic images of that horrible day. In fact, the Observer New Review (London) republished it in 2011 as the 9/11 photograph. In Hoepker’s words, he saw “an almost idyllic scene near a restaurant — flowers, cypress trees, a group of young people sitting in the bright sunshine of this splendid late summer day while the dark, thick plume of smoke was rising in the background.” By his reckoning, even though he had paused but for a moment and didn’t speak to anyone in the picture, Hoepker was concerned that the people in the photo “were not stirred” by the events at the World Trade Center — they “didn’t seem to care.” Hoepker published many images from that day, but he withheld this picture for over four years because, in his view, it “did not reflect at all what had transpired on that day.”
I have regularly argued that in investing, as in most things in life, disconfirmation is more valuable than confirmation (see here, for example). In other words, we learn more from what doesn’t work than from what does. That’s largely because induction is the way science advances.
We want deductive proof, but have to settle for induction. That’s because science never fully proves anything. It analyzes the available data and, when the force of the data is strong enough, it makes tentative conclusions. But these conclusions are always subject to modification or even outright rejection based upon further evidence gathering. The great value of data is not so much that it points toward the correct conclusion (even though it does), but that it allows us the ability to show that some things are conclusively wrong.
In other words, confirming evidence adds to the inductive case but doesn’t prove anything conclusively. Correlation is not causation and all that. Thus disconfirming evidence is immensely (and far more) valuable. It allows us conclusively to eliminate some ideas, approaches or hypotheses. Continue reading →