The words conscience and consciousness can cause a good deal of confusion, due in some measure to the similarities in their spelling and pronunciation, so let’s have a proper look at them.
Conscience /ˈkɒnʃəns/ can mean one of the two things:
the part of your mind that tells you whether what you are doing is morally right or wrong; i.e. we can call it our inner moral compass.
I knew I’d done nothing wrong and so I told him the truth with a clear conscience.
If you’ve done something you shouldn’t and know it, you probably have a guilty or troubled conscience.
Steve’s guilty/troubled conscience made him tell Anna he’d been cheating on her.