The denial of moral responsibility in materialism is not restricted to the Christian worldview. Secular or religious, deniers often try to undercut free will as their starting point. In the latest assault on moral responsibility,
so-called psychologists Joshua Greene and Jonathan Cohen argue that, because the brain determines everything we do, we are not responsible for our actions, and that the law should not be punitive but rather be consequentialist.
That's the nice way of putting it. As I see it, while I am not against consequentialism in principle, in this case consequentialism seems to me simply to mean : treat man as a meat machine and try to control it. I've seen the same argument applied to politics, calling for more welfare because after all man has no free will and therefore has no responsibility whatsoever for his own outcomes. Therefore, total control of society is desirable. The fallacy of Special Pleading, in both cases, seems to apply. Neither the judge, nor the politician, nor the person who proposes consequentialism, is any more than a meat machine either, in this perspective, so these beliefs are self-referentially nonsensical.
People who should know better often use properties of the brain to try to deny free will. The article I linked argues that, because we can trace all thoughts and attitudes in the brain - because we are in theory not uncertain about anything in the mind - there must be no free will. Others argue that free will does not exist because we know neurologically that our choice to press a button follows the impulse to press it.
But here's the problem : we have no more reason to think that free will expresses itself in neurological uncertainty, or neurological temporality, any more than we have reason to think that, say, the concept "red" is encoded by neurons that glow red, or that our perception of a violent event should hurt the perceiver's brain. We have no grounds to assume anything about how any mind experience is expressed in the brain until we actually find it. To assume that free will "must be expressed" in a certain way is to hold a belief about it that is not based on fact.
This pseudo-scientific anticipation is much like homeopathy and its principle of "like cures like". It's not because something has a metaphorical resemblance to something else that both have a relation, and the absence of such a resemblance does not mean there is no relation. Aspirin doesn't look like a headache, but it still cures headaches.
And yes, before the Objectivists start getting impatient, I haven't forgotten that free will is axiomatic. To deny free will demands one to direct one's attention to facts and arguments, and therefore is automatically self-refuting. It's not really the epistemic aspect that interests me, in this case, but rather people's unspoken assumptions that lead them to deny free will.
The more important unspoken assumption, however, is the assumption that we are separate from our brain. And this is where the pseudo-scientific side joins Christianity fully. Both assume that :
(1) It is a necessary precondition of moral responsibility that "I" decide what I am doing.
(2a) If materialism is true, "I" am not morally responsible because "my brain" makes "I" (me) do things.
Yet from the materialist standpoint, this is wholly incoherent, as "my brain" is part of "I". The proposition then becomes :
(2b) If materialism is true, "I" am morally responsible because part of "I" (myself) makes "I" (me) do things.
For the argument that something exterior to myself ("the brain") is nullifying my moral responsibility fails, as "the brain" is not exterior to myself.
In essence, both the Christian and the subjectivist claim that moral responsibility is only possible if the mind-brain connection is severed - the only difference is that only the Christian claims that the connection is indeed severed. But as in most things, both hold to the same epistemic premises. However, it is obvious that moral responsibility is only possible if the mind-brain connection is maintained.
Suppose that the mind had no causal relation to the brain, and that I have a "soul". Thoughts pop in my mind with no relation to reality. One second I love all mankind, the next I desire to kill. How can I possibly be held responsible for these thoughts ? They are not the result of any reasoning on my part, since reasoning would require empirical evidence, which would require a causal link to reality. They are not the result of my personality, since the personality is part of the brain. So how am "I" in any way responsible for my desires ? This seems quite impossible.
On the other hand, if there is a brain-mind identity, then my thoughts and desires are part and parcel of my identity, and manufactured by myself, and there is no grave problem in this case. If I desire to kill, I am responsible for such desires. Even if I had the bad fortune of being born with criminal impulses, I am still capable of repressing such desires (as the vast majority of such people can, a handful of serial killers notwithstanding), armed with a solid education and a strong sense of values. Even if I may desire to kill, I know that such actions are detrimental to my life. BTK is not a good life example.
Regardless of the things I had no choice upon, I still, in the end, choose to act in a certain way, as opposed to another. The ultimate responsibility lies solely on my shoulders. As an individual, I take control of this responsibility and make it mine.