When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the state of science.
The revolutionary idea that defines the boundary between modern times and the past is the mastery of risk; the notion that the future is more than a whim of the gods and that men and women are not passive before nature. Until human beings discovered a way across that boundary, the future was a mirror of the past or the murky domain of oracles and soothsayers who held a monopoly over knowledge of anticipated events.
The two quotes that start this chapter capture the essence of beauty in measurement and its primary deliverable: metrics. Lord Kelvin’s message is that there is no science without metrics. Peter Bernstein’s statement is about risk, which is conceptually related to security. Dr. Bernstein states that metrics free you from the morass of being a prisoner of the past or, even worse, dependent upon fortune tellers—certainly key objectives of science, in general.
For these reasons in themselves, metrics are beautiful—at a conceptual level. What about in practice? In particular, what about the application of metrics for protecting ...