Proudly, a child learns that one plus one equals two. It is a useful way to organize and abstract the world, the gateway to control. Numbers are a magical and important tool of civilization. We cannot imagine life without them.
But we must always be careful to understand the limits of such abstraction. No real world manifestation is truly equal to another. Even a molecule is different from all other molecules by virtue of its leptons and quarks.
A child can understand this. One rock plus one rock is two rocks. But if one is a pebble and the other a boulder the idea seems a little silly. If two are equally sized but one is made out of gold, other considerations come into play.
We find that constraining definitions are required _ are we counting apples, oranges, or a mixture? By the time we load on all the qualifications, one plus one equals two seems a lot less glorious and absolute.
We thus need to be extremely careful with numbers, even before we get to concepts of “many.” And that is the root of the problems we have with statistical valuation, and the application of enumeration to ethical concepts.