By Lisa Schwarzbaum
Updated December 03, 2008 at 05:00 AM EST

What Doesn’t Kill You, a tough, authentic street drama born, bred, and shot in the ? no-spin zone of working-class South Boston, doesn’t spell out the origin of the movie’s ? title. Nor does it complete the second ? half of Friedrich Nietzsche’s famous ? declaration to which it alludes — the part about making you stronger. There’s no need for moralizing when the actions and ? consequences are so clear and the story — of two local toughs at a critical juncture ? in their lives — is so strikingly free of ? romanticized Southie swagger.

It helps, surely, that Brian Goodman, an actor making a strong directorial debut, tells a version of his own life story here. And it’s evident that a serious commitment to the tenets of 12-step recovery programs keeps him modest and honest about what works for getting stronger (if you keep working it).

In a harmonious pairing of temperaments and talents for portraying flawed men who enforce their codes of ethics on a sliding scale, Ethan Hawke and Mark Ruffalo play Paulie and Brian, respectively — best friends from the Southie hood who fall under the sway of a local crime boss (played with ? authority by Goodman). Paulie, single and loving it, keeps his head clear for business. But Brian, a husband and father under pressure, burrows downward into drugs and drink. (Amanda Peet is terrific as Brian’s worn-down wife, sick of seeing her man ? disappear before her eyes.) Goodman the filmmaker eloquently conveys what ? Goodman the addict learned: that the climb back up and out is hell — and worth it. B+