This one is an extremely common usage, and too often overlooked by editors too.

The liberal minimalist approach is exemplified by the Canadian political philosopher, Joseph Carens.

changed to

The liberal minimalist approach is exemplified by the Canadian political philosopher Joseph Carens.

If there is only one Canadian political philosopher to date, the apposition marked by comma is right. But there can’t be and there is not one. Delete the comma, fast, fast! This is a too common mistake by authors and one that sometimes could lead to an unintended different sense to a reader.

Advertisements