Lord Kelvin's dictum on measurement - applies to finance

 

“When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts advanced to the stage of science.”  - Lord Kelvin's dictum 

This is a good rule to follow in any financial work, yet once you are done measuring, you have to focus on what cannot be measured and make some conjectures for what is not explained.

As an aside:

Ogburn, a onetime head of the Social Sciences Division, was also responsible for perhaps the most contentious carving on campus. Curving around an oriel window facing 59th Street is a heavily edited quote from Lord Kelvin: “When you cannot measure, your knowledge is meager and unsatisfactory.” Ogburn was a hearty proponent of quantification in the social sciences, a view that some of his colleagues definitely didn’t share. In a 1939 symposium, economist Frank H. Knight Jr. (a teacher of Milton Friedman, AM’33) snarkily suggested that the quote be changed to “If you cannot measure, measure anyhow.” Fellow economist Jacob Viner chimed in with a suggested addendum: “If you can measure, your knowledge is still meager and unsatisfactory.”