A new TCA article by Laura Prudom (@LauinLA) from aoltv.com gives us a little more insight into Gale's character in The Secret Circle:

"Diana might not be the villain of the story, but her father, played by Gale Harold, is certainly toeing that line. "I'm not sure if he's even sure what he's up to," Harold wryly admitted. "He's very drawn to bringing back something he thought he had his hands on when he was younger. He needs this new generation [of witches] to come and bind together and through that, my character and Natasha [Henstridge] utilize that. He has to make sure that everyone around him assumes that he's just an upstanding nice man, that he's not just a bad guy."

If the writers do their job right, though, "you'll understand why the villains are doing what they're doing," Williamson said. "There's a reason for their actions, and their kids will come to understand their parents in ways they never would've expected from the pilot.""
TCA Report: 'The Secret Circle' Explores Magic, Family and Love Triangles