Abortion, gay marriage, contraception, pre-marital sex, the death penalty, euthanasia, school prayer, guns — the list of issues that define the culture war is long. But what if underlying them all is a deeper cultural fissure that determines the shape of many of the more superficial policy disputes?

I'm talking about the fault line separating those Americans who believe in the reality of sin from those who do not.

I don't mean anything as elaborate as the classical Christian doctrine of original sin — a sin undertaken by an ancestor that's passed down as a stain on subsequent generations. Neither do I mean a list or ranking of particular sins. Those can vary widely from one faith tradition to another, and the differences don't much matter to the more fundamental cultural gap I'm talking about.

By sin, I mean the general view of human motivation and behavior expressed perhaps most clearly and succinctly by St. Paul in the Letter to the Romans: "I do not do what I want, but the very thing I hate… I have the desire to do what is right, but not the ability to carry it out. For I do not do the good I want, but the evil I do not want is what I keep on doing." (Romans 7: 15, 18-19) 

This is a vision of a human being as a creature who knows what's good, wants to do it, and yet actively chooses to do otherwise. Sin is a turning away from what's right and choosing to do wrong. 

Consider an example: I'm a consultant visiting a large, wealthy firm with many thousands of employees. As I stroll unaccompanied down a corridor, I pass an open office and spy a large pile of cash on a desk. I'm alone. The office and hallway are empty. I know there are no security cameras in the area. I can almost certainly enter the office, pocket a handful of cash, and escape unseen.

According to St. Paul, my thinking as I reach for the money will run as follows: "I know that stealing is evil, and I don't want to be evil, but I could buy so many wonderful things with this money. I really shouldn't be doing this, but I can't resist the cash, even though I know that stealing is wrong." 

That's sin in action: overwhelming my conscience, my innate knowledge of good and evil, motivating me to act against what I know to be right. The urge to sin can feel overpowering, but it can't be conceived as something foreign moving through me, causing my actions against my will. It's my own will that is sinful. I know what is right, and yet I actively choose to act otherwise — because of an innate tendency toward disobedience, because I want more good things for myself than I can secure through right behavior, and because part of me thinks that if I can elude detection and punishment by human authorities I will have gotten away with my act scot free.

It is this idea of a fundamentally sinful humanity that inspires the harsh, punitive sentences of our criminal justice system — including capital punishment. It also provokes visions of merciless suffering in hell after death. We deserve severe punishment because we are free agents who knowingly choose to do what we ourselves know to be wrong.

On the far side of a chasm stands a very different idea of humanity — one elaborated by Socrates and other characters in several Platonic dialogues. It holds that virtue is knowledge and vice is ignorance. 

Let's return to our example to see what this implies.

I look into an open office and see a pile of money. On the Platonic view, if I refrain from pocketing a handful of cash, I do so because I'm convinced that it's good to abide by the moral stricture against stealing — and better than enriching myself. If, instead, I grab some money and walk away, I do it because I'm convinced that having the money is good — and better than being moral.

Two contrary opinions are in play: money is better than morals, or morals are better than money. One must be right, and one must be wrong. If I steal the money (having convinced myself that money is better than morals) and I get caught, then the proper response is to educate me about the error of my ways. My ignorance led to vice, and knowledge will lead to virtue. I need to be taught why I was wrong to think that money is better than morals. I certainly don't deserve to have suffering inflicted on me — either in a torture-chamber hell after death or in a hellish human prison — any more than a person ever deserves to suffer for having made an error. (Plato's dialogues teach that no one intentionally makes a mistake.) 

For Plato, the concept of freely chosen sin — of knowing what is good but choosing to do otherwise, and of punishment as imposed suffering for having made that evil choice — makes no sense. Evil is always the result of an unintentional mistake, and the only just punishment is education or rehabilitation. 

Plato's dialogues may have presented the fullest and most radical exploration of this view, but versions of it animated various strands of Enlightenment thought, and to this day it continues to influence the way many liberals and progressives approach questions of criminal justice and related areas of public policy. 

When someone commits a crime, do your instincts tell you to blame the perpetrator's upbringing, background, education? Do you think that the best form of punishment would involve rehabilitation? Then you are, at bottom, a Platonist who rejects the idea of sinful depravity.

On the other hand, do you tend to blame the perpetrator's actions on a malicious will and presume that, however worthwhile an education might be, it will never eliminate the possibility of evil, because evil is chosen despite knowing what is good and right? And do you therefore think that the best form of punishment is one that imposes suffering for the sake of retribution and deterrence, hopefully to help scare this and other potential criminals away from making similarly bad choices? Then you are, at bottom, a Pauline believer in the reality of sin.

This either/or way of presenting the two views is overly simplistic. Plato was well aware that teaching virtue can be a challenge (and may often be impossible), just as believers in sin typically think that moral education is extremely important in shaping and strengthening a person's conscience. 

Still, the distinction is real and important — and its implications touch on areas of our cultural life far beyond criminal justice. It helps to explain, for example, the very different ways that Platonic liberals and Pauline conservatives approach sex — with the former willing to trust in the power of rational sex education to help shape behavior, and the latter much more concerned about their children succumbing to sinful temptation no matter how many rational arguments they're exposed to. 

What's clear is that, if you're interested in exploring our cultural conflicts at the highest levels, you could do worse than pondering Plato and Paul.