Original Sin. noun. An inborn guilt-worthy moral limp--in other words, a contradiction in terms.
Any fetus may acquire DNA that will eventually hobble its adulthood. There may be inborn physical defects. There may be inborn mental defects. There may be inborn psychological defects. All congenital, none chosen.
What we must insist on--against original sin--is that characteristic traits (those we are born with) cannot be morally blameworthy.
Original sin says we acquired a sinful essence owing to the errors of our remotest parents. Adam and Eve's aboriginally calamitous garden party bequeathed to all of us a nature tending toward sin. And when we do actually get around to behaving as our sinful nature pre-disposes us to, we are guilty, blamable, chargeable.
This cannot be correct. If we are born with a defective moral compass, that should excuse us and not expose us to blame.
No one should be morally judged for characteristic traits within themselves because moral judgment of persons only applies when persons make free choices, and if we have a characteristic trait called original sin that inevitably leads us to enact sin, we are not truly free when we enact sin, and therefore we cannot be blamed for sinning.
Original sin is actually a theory of moral determinism, and moral determinism can have nothing to do with sin or moral guilt. A 'born sinner' is about as perfect a contradiction of terms as can be contrived.
Let's look at this through the lens of inherent physical defects. Can we blame someone for being unable to run if they are born with defective knees? Can we blame someone for not being able to add numbers correctly if they are born with dyscalculia? Can we blame someone for not hearing if they are born deaf?
No, we don't blame these people. We excuse them. Similarly, if sin is inherent we cannot blame the actor of sin (though we may indeed deem the actor's act a disvalued, denounced deed).
Laying blame for a characteristic trait is a major flaw in the idea of original sin. To repair this, that is, to retain original sin by refashioning it in a way that is not self-contradictory, theologians would have to do one of two things.
First, theologians could say that humans do inherit a moral taint, but far from imputing blame to humanity for actions made under the influence of that inherent defect, the inherent defect exempts from guilt. It might be that an Adam or an Eve in a state of innocence and not being created with a sinful nature could be blamed for sinning. But every other human being staggering under the weight of inbuilt moral ineptitude must be immune from judgment, and certainly from damnation.
(Shakespeare's Falstaff sees this and defends his errant ways from a censorious Prince Hal by saying, "Thou knowest in a state of innocency Adam fell, and what should poor Jack Falstaff do in the days of villainy?")
Second, theologians could abandon the notion that original sin creeps its way into the interior of human nature and instead adopt a position that original sin taints culture in such a way that all humans are morally affected by a social atmosphere of sin. This atmosphere of sin, though a powerful influence, does not compel sinning, and therefore the sinner is not excused and may be judged guilty.
For a third choice, theologians would not seek to retain and repair original sin but discard it. The story of Eve's transmissible guilt to heirs in perpetuity is as fabulous as the Phoenix and cannot be rescued even by metaphorical and allegorical exegesis.
So, theologians, look for another cause for our moral incompetence.
Evolutionary psychology suggests evolutionary drag: our deep posterior reptilian and simian brain slogs behind the civilizing moral rules of our more recently evolved frontal lobes.
Curiously though, like original sin, evolution also speaks of ancestral inheritance, and such an inheritance might argue for a measure of determinism. Some people could be born with deficiencies that will compromise moral choices; and where this is the case, as a characteristic quality, it must attenuate guilt. A wise Judge will see the mitigating role of a very low IQ even in a heinous murderer.
The doctrine of original sin first appeared in the early centuries of Christianity and was probably really about the savior Christ. Wanting to seal everyone up in a need for Jesus, even a half-a-minute-old infant had to be a sinner requiring the saving ministrations of Christ's cross.
But the fashioners of original sin did not see the inherent contraction of inherent sin. No one can be a born sinner, especially one born morally obtuse.