Hume: Moral Responsibility

Part of Hume's version of compatiblism involves moral responsibility. Hume says that his compatibilism works with holding people morally responsible for their actions. He says human behavior falls in line with the natural chain of cause and effect. If this were not the case, then human behavior would be subject to randomness. Praise and blame are only justified, according to Hume, if actions are performed as a result of a person's character. I agree with Hume on this point, because if everything was random then we wouldn't be able to hold people responsible for their actions. If John murders his family, we cannot punish him because it was purely an act of randomness (this kind of reminds me of when people plead insanity and things like that--they couldn't help what they were doing or didn't understand the consequences of their actions). From here on out, however, I'm a little confused about Hume's argument. He goes on to say that we can justify praise and blame with determinism, and that in turn justifies freewill. That all seems a little out of order to me. First of all, Hume's earlier description of what justifies praise and blame sounded to me like freewill---if people can freely make the decision to murder their families, they should be blamed for it. If it was determined that an individual was going to murder his family, should he still be held responsible? Because if the act was determined, then he could not have done anything to stop it. So I don't think that determinism entails holding people morally responsible. I might agree that if determinism DID entail holding people morally responsible, then we could figure that we do have freewill. But Hume didn't argue for anything like that, so yet again, I disagree with him.