Are You a Man, a Dog, or a Monster?

"Are you a man, a dog, or a monster?" Alucard has asked this question (in some form) on more than one occassion and to more than one person. As I was trying to determine Hellsing's central theme, I decided that this question was an important part of it. I began to wonder, what exactly is a man, a dog, or a monster? What makes them what they are?

I think that a man is a person who makes choices and accepts the consequences of those choices.
I think that a dog is a person who allows someone else to make choices for them.
I think that a monster is a person who makes choices without thinking them through and without accepting the consequences of those choices.

If you have your own definition of what a man, a dog, or a monster is, or what makes them what they are, I'd be very interested in hearing it.