What Is the First Principle of the Practical Intellect?

I'm trying to expand the concept of what counts as an evil action or as a bad action. I think it's possible to say that an action is both bad and not a sin. So you can consider, I'll take a biblical example, the midwives in Egypt lying to Pharaoh. Did they sin? I don't think so precisely because God ends up rewarding them for their action. But he says that they didn't realize that lying is wrong. They were acting in a court with their conscience.