The Mint Theater Company is doing what it does best: acquainting audiences with a long-ago play, and author, most people have probably never heard of. Here the author is Harold Brighouse, and the play, Garside’s Career. Billed by the Mint as “bright, witty political satire,” it traverses more genres than that, also taking in domestic drama and commentary on relations between the sexes, and serves as parable about misplaced ambition. The production is mostly excellent. The bright and the witty are relative.