Conscience was a personality trait that helped an individual determine right from wrong.
Malador claimed to have had his conscience surgically removed, allowing him to act with no concern for the consequences. (AUDIO: The Guardians of Prophecy)
Among other things, Miss Kizlet was able to control the conscience in the people whom she had uploaded into the data cloud. By manipulating a numerical values for conscience on her tablet, she was able to, as one of her underlings once said, "hack into" people's personalities and instantly change their conscience metric. (TV: The Bells of Saint John)