In this meme presenting a sentiment from F. A. Hayek, one of the reasons why no two individuals are alike is that each has an infinite number of characteristics which have values, as well as an infinite number of relationships among those characteristics.
If I were to begin to tell you how A was a distinct individual when compared to B, I would never complete the task of identifying all the differences. Most characteristics are not atomic, ie. Broken down to its smallest component, an indivisible piece. Most characteristics are complexes of systems and subsystems.
For instance, no two sets of fingerprints, irises, retina, or dna are the same. The differences for slow-motion mankind are infinite, not to include the complexity that each object must occupy its own exclusive location in space/time/probability.
Given the profundity of these differences, how could you devise rules that would separate two uniquely born creatures for purposes of making one a master and the other a slave? How do you decide that the person with the redder skin must forfeit land to the person with less red skin? Color itself, if not infinitely variable, has as many possibilites as there are living individuals on the Earth.
Let's say for the sake of argument, that all human characteristics are equal and each can have only one value, out of two -- black or white. Now, posit that there are only two characteristics, hair color and skin color. With an individual there are 4 possible combinations. A has black hair, black skin or white hair, black skin or white hair, white skin or black hair, white skin.
For two individuals, there are 4 chances to be alike, but 12 chances to be different. With only 3 individuals or 3 characteristics, the numbers get out of hand very quickly. Of course, there are billions of individuals and likely an infinite number of characteristics, some of which can have an infinite number of values. Where to begin to make rules (legal fictions) which can separate one individual from another.
We normally stoop to the practical measure of declaring one or a few characteristerics to be more important than other combinations. But how do we do that? Is height more important than width. Maybe. Is age more wise than youth? Maybe. Is experience worth more than intelligence, or is a combination of the two worth more than either alone? What are the scoring rules?
What combination of characteristics gives us an effective probability of identifying the better master compared to the better slave? Is there a combination of tweaks or random generators that will magically refine the results?
Many of us cite Ockham's Razor, which we believe says "Keep it simple, stupid -- KISS," but this heuristic rather says "Make it complete -- don't omit the necessary, but don't attach the unnecessary." How do we guage the "necessary."
We have recently seen Congress tie itself in knots trying to please a POTUS who has no idea what he wants, who is at a loss as to which values belong to which characteristics of which yearnings. This is to say nothing about the arcane rules of procedure and counting that confound a determination of truth in any concrete way.
Sometimes, it appears that we do things to hedge against results. If our procedure is kinky enough, it can explain away all of the unforeseen consequences. And we are left with excuses to try even more ridiculous flights of stairs in buildings other than the one we would hope to climb.