capitalization of a common noun

If you substitute a common noun for a proper noun, e.g., refer to a person as his/her title without using that person's name, do you capitalize a title that would normally be a common noun? P.S. I failed to note that I am not referring to a situation where a writer has one person addressing another in the text. The proper noun/common noun question is about referring to/describing someone only by his or her title. I think too subsequent references would always be to the dean, the chairperson, not a dean or a chairperson. Hope this helps and am grateful for everyone's input.

In general, yes. For example:

• "He met the president," vs. "He met the President of the U.S.A."
• "She was a minister," vs. "She is the Minister of Defense."

BTW, a proper noun that should not be capitalized: e e cummings.