A "John Doe" [1] presumably still has a name, even if it's unknown to you specifically. That would be a counter-example to "You always know a person's name", no

A "John Doe" [1] presumably still has a name, even if it's unknown to you specifically. That would be a counter-example to "You always know a person's name", not to "People have names". [1] https://en.wikipedia.org/wiki/John_Doe https://en.wikipedia.org/wiki/John_Doe