Ensign Weinberg was a 23rd century Human man, a Starfleet officer who served aboard the Federation starship USS Enterprise in the year 2270, and was a trained psychohistorian.
On completion of his tour of duty aboard the Enterprise, Weinberg hoped to sign on with the Federation Diplomatic Service. (TOS - Mudd's Angels short story: "The Business, As Usual, During Altercations")