The subconscious self.
People talk about god and the voice they hear. Guaranteed that's what that is.
I don't believe them to be entirely wrong either. It's kind of like calling the earth a sphere. Yeah, it's not a flat object, but it's not a perfect sphere either.
Ultimately you have the most control over you. Don't let you fool yourself into thinking you don't. Sometimes other people manage some amount of leverage on peoples decision making. It can be for the good, or the bad. Hell, it can even be neutral, and anywhere in-between.
The reason I bring this up is because somebody on my facebook feed was upset at the prospect he'd been influenced by other people. He then began to state how only the week willed allow themselves to be influenced by others. This is sort of true, but at the same time, when somebody raises you, they teach you things that are going to have influence over you. The friends you hang out with and want to impress, have influence over you. This isn't a rant, his friends got to him before I did, and he's come to a better understanding as a result. Just something to think about if you otherwise haven't.