I once went through a phase where I was very agnostic with regards to the meaning of the word person.* I wondered what exactly we meant when we said that God is three persons in one divine nature? I got somewhere eventually. I got my ducks in a row by thinking about what it meant to say that the Holy Spirit was a person. Here I arrived at my answer by following a line of reasoning similar to this – taken from Wiki.
The duck test is a most erudite and scholarly form of inductive reasoning. This is its usual expression:
If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.
Amen and quack quack!
On another note … a quote from one of my favorite authors:
“If it looks like a duck, and quacks like a duck, we have at least to consider the possibility that we have a small aquatic bird of the family anatidae on our hands.” ~ Douglas Adams
*Note: I am not 100% on this as yet.