The brain happens to be a meat machine.
We turn to quantities when we can't compare the qualities of things.
An ethicist is somebody who sees something wrong with whatever you have in mind.
This is a tricky domain because, unlike simple arithmetic, to solve a calculus problem - and in particular to perform integration - you have to be smart about which integration technique should be used: integration by partial fractions, integration by parts, and so on.
You don't understand anything until you learn it more than one way.
Minds are simply what brains do.