Dear Daughters,

Over the past couple of decades, the desire for numerical metrics has spread far and wide in our society. These days, everywhere you look, people are trying to quantify something, ostensibly in order to measure it more accurately. Schools want to quantify learning by means of standardized test scores and grade-point averages calculated out to the thousandth place. Businesses want to quantify human performance through numerical end-of-year reviews that convert managers’ judgments into digitized data (as if that automatically made them more objective). People want to quantify their own health and fitness by counting steps or calories or points.

There are plenty of good reasons for these efforts, and much good could surely come of them. But we need to be wary of a potential error that lurks near the heart of our metrical lust—the error of mistaking a measure for the thing measured, of confusing the things we count for the things that actually count for us.

These are almost never the same.

The signature case in which they are the same is pure financial return: Here we measure in dollars and cents when what we’re after is (just) dollars and cents. No question this is an important exception. Upon it stands the whole edifice of capitalism. But note both that capitalism has its limits and that the case of pure financial return is still an exception.

In the vast majority of cases, the things we measure are manifestly not the same as the measures by which we assess them. The health of a man is not reducible to his height or his weight or his body-mass index. The potential of a woman is not reducible to her IQ score or her grade-point average or the mark on her last performance review. The importance of an idea can’t really be measured in likes or retweets or clicks without recourse to vexing questions about its good old-fashioned truth. Happiness can’t be summed up in dollars and cents. Even the likely long-term value of a business can’t be assessed without consideration of its leaders’ honesty. (If you doubt this, look up Enron, Lehman Brothers, Bernie Madoff, or any of a long list of accounting scandals.)

Honesty, truth, human potential, happiness, health—these are all attributes that we can, and sometimes do, attempt to measure via metrics. But the attributes are not, and never will be, simply the same as the metrics we devise for them. And in our drive to quantify and calculate, to recast the world in sharp algorithmic images, we should be careful not to substitute their metrics for them. We should accept, instead, that many such attributes can only be properly assessed through faculties other than arithmetic–through empathy, contextual reasoning, subjective understanding, or what Aristotle and my mom both called “good judgment.”

We should get comfortable with the notion that the world includes rough edges, nuances, and sometimes-contradictory complexities. And we should recognize that the best truth we can tell often isn’t black or white, or even some shade of grey, because the world we actually see is a kaleidoscope of overlapping shades and colors and meanings. It includes all sorts of aspects and attributes, some of which can’t be counted–including honesty, truth, human potential, happiness, and health. Not to mention honor, bravery, kindness, helpfulness, purpose, beauty, love, and so on.

Not everything that matters is a metric, or even measurable by one. And not every metric matters. For practical purposes, this means that whenever you see a metric, you should ask at least two questions: “What are we really counting here?” And “Is that what really counts?” And you should always remember that the latter question is the one that matters most.

Don’t be afraid to use your own good judgment to answer it. Otherwise you might wind up measuring yourself, and your world, by the wrong yardsticks. You might lose track of the fact that keeping score only matters if you’re playing a game worth winning–and that, in the game of your life, you get to help decide what winning means. You get to decide what really counts for you. The metrics only matter in light of that.

I love you (count on it),

Dad