James O'Shaughnessy

Historically, we have always seen reversion to the mean. After stocks have had an unusually great 10 or 20 years, they typically turn in subpar results over the next 10 or 20, and after bad 10- to 20-year stretches, the next 10 to 20 tend to be above average.

Reality does not easily give up meaning; it's the biographer's job to clobber it into submission. You're meant not only to tame it but to extract substance, to identify cause and axiomatic effect. You subsist on the tactical omissions, the hollow words, the oddly unconnected dots.