I once told a colleague that I didn’t believe in objective marking, and she enthusiastically agreed. “I don’t think it’s possible to be objective,” she said.

I told her that I didn’t think we should try to be objective, or even that objectivity is an admirable goal. “The world hasn’t been objective with our students, so we shouldn’t try to pretend there is a level playing field when we are judging their performance.”

She was puzzled by the assertion, so I told her that I don’t think we can judge...