The National Football League is the most popular sport in American history.*

We know this anecdotally and statistically. What does the majority of America do on Sundays? From my experience, they watch football. The ratings bare this out. This week, a terrible Monday Night Football game outdrew a New York Yankees playoff game. But the league's greatest asset is also its achilles' heel.

The NFL's influence is so massive and all-encompassing that when something polarizing happens—good or bad—it's pretty easy to just skip the portion of the discussion where we talk about exactly what happened. Because whatever it was, with all the highlights and halftime shows and news alerts, you know that everybody saw it themselves. So we take the event for granted, skipping ahead to what it means for the future, how it compares to the past, or what effect it has on the present. Everything gets analyzed within a much larger framework.

That's sort of what we all did on Monday. In Monday's Designed Rush, Mike Tunison talked about the Great And Unavoidable Helmet-to-Helmet Freakout:

With a spate of helmet-to-helmet shots and resulting concussions seen on Sunday, the full-on hue and cry about the dangers of head injuries in professional football is back at full pitch for the first time in probably... days? Weeks? It's going to be a regular discussion for a while. Every time this happens, the debate will start anew. This is at once predictable, completely understandable and also incredibly frustrating because no one really has a sound idea about how to fix the matter.

It's not a bad thing, but as we prepare to dig in and discuss what can be done here, we should remember what prompted the discussion in the first place. So, here are three separate stories from this past Sunday that made me feel guilty for loving football.

1. Todd Heap Laying Motionless on the Field. The Ravens-Patriots game was pretty much perfect for a football fan. Two well-coached teams going back-and-forth, battling to a tie after 60 minutes, with New England prevailing in OT. Even a victory for evil-Bill Belichick couldn't dampen my enthusiasm; that was just a kickass game.

But toward the end of the first half, it looked like Todd Heap was dead on the field. It came just a few minutes after Patriots' Brandon Merriwether had barely missed on a head-first spearing attempt that would have A) Broken up a Ravens touchdown and B) Risked serious injury to both players. Fast-forward a few minutes, and there he was again, leading with the head. But this time he connected.

After a few harrowing minutes with Heap splayed out motionless on the turf, he left the field, and we could all breathe a sigh of relief. When he came back later in the game, we could even take it as a reassuring sign: He's back. He must be okay. It wasn't as bad as it looked.

But how do we know how bad it was, and whether he should have been out there?

2. Dunta Robinson and DeSean Jackson and War. Here's a perfect example of something that's prompted a much bigger discussion, obscuring a more basic problem: Robinson's hit wasn't that special.

Kevin Kolb hung DeSean Jackson out to dry over the middle, and Dunta Robinson did what a defensive back should. Light. Him. UP. Like they say on NFL Countdown, "BOOM!" Football players are taught to do it, and football fans are taught to love it. Last night on Monday Night Football, they ran a highlight reel of Chuck Cecil hammering opponents during his career, and Jon Gruden waxed poetic, football style: "He would KNOCK. YOU. OUT. Chuck Cecil was a tone setter. There was fire and brimstone in that body." For better or worse, brutal hitting is woven into how we understand the game.

And Cecil's hits were awesome. But Sunday's hit knocked both players out of the game.

The officials later ruled that DeSean Jackson was defenseless, but that's not a reflection on Dunta Robinson. Or it shouldn't be. He was a defensive player trying to do his job, with a split second to make a decision. Look at Dunta Robinson's eyes in this picture, while Jackson sits dazed in the background. With this stuff, even the villains are victims.

A lot of people like to use war analogies to glorify the "battle" that takes place on the football field each Sunday. But here we had mutually assured destruction in a literal sense. Not a "war in the trenches" with NFL Films music playing in the background, but two spectacular, impossibly graceful athletes staggering off the field bleary-eyed and beaten. A lot closer to real war than the war analogies, no?

3. Aaron Rodgers played. A week after suffering a concussion against the Redskins, Aaron Rodgers was out there in Green Bay, starting for the Packers. He's on my fantasy team, and had 22 points this week. He gave the Packers a chance to win. But in a year when the whole NFL's supposedly getting serious about concussions, it makes you wonder.

Is there an exception when it's a star player that's essential to victory, or did Aaron Rodgers just happen to recover faster than all the other quarterbacks that have been sidelined with concussions this year? That's not a snarky rhetorical question. It's genuine, with genuinely unknowable answers.

And it's a microcosm of what's hanging over the NFL right now. Are players risking their own well-being by playing football? We really don't know the answer, but more and more, the answer looks like, "Probably." And you can't blame us if pictures like this scare us into fearing the worst.

Even though each incident gave me pause as a fan, they're remarkable not for the concussions or some glaring lack of precaution, but because ultimately, none of it is that remarkable. That's just the game.

The defensive players that laid people out this weekend may have been leading with their head, and Desean Jackson may have been hung out to dry by Kevin Kolb, and Aaron Rodgers may have been toughing it out for his team. But the problem isn't football players, football equipment, and maybe not even football's rules. The problem is that those guys were risking injury by playing football.

It's not a bunch of demonic defensive backs out there wreaking havoc on these poor "defenseless receivers." On the whole, NFL players get hurt because there are certain physical realities that come into play when you put a bunch of gigantic, high-speed athletes on the field at once. When everyone runs a 4.5, everyone's stronger than ever, and they're all wearing helmets, helmet-to-helmet hits will happen, and they will do serious damage.

The NFL can fine and suspend players for vicious hits, but suspensions won't change how big and fast the players are, and it won't change the culture that compels players to return to the field earlier than they should, or fans to clamor for bigger hits and more games. This is football.

On Monday I took a break from thinking about concussions and the 1-4 Cowboys and Brett Favre's penis to talk to a friend that's not a sports fan. We were debating the merits of a program in Great Britain that was offering drug addicts about $320 to be sterilized, ensuring that they won't have kids and then raise those children in a broken home, ultimately creating more problems for society.

Depending on your perspective, it's either pragmatism at its best or cynicism at its worst. You can make convincing arguments for both sides. And it's more analogous to the NFL than you'd think. As football continues its evolution in the 21st century, the moral gray area typically reserved for debates like "addict sterilization" has begun to creep into football, one arena we could always count on for an escape. These days, the NFL makes us feel just as uncomfortable as the real-life dilemmas we want to escape.

For instance, NFL players don't have guaranteed contracts, and they're paid less than you think. Chris Johnson is the best running back in the NFL, and he makes just $2 million. That sounds like a lot, but the best shooting guard in basketball makes $20 million. But NFL players are quite literally spare parts in a much bigger machine. Teams invest as little as possible in them, use them until they break, and then they get a new one. Fans root for their favorite player until he gets cut to create cap space, and then they get a new one. Most of the players lack the education necessary to manage their money, leaving them with little to show for after it's all over. Oh yeah, and the shelf life for pro football players gets shorter every year, all while ticket prices skyrocket and the NFL signs billion dollar TV contracts, and franchises appreciate by the hundreds of millions. When you look up close, it's not pretty.

And that's all before we talk about the head injuries that prompted an ex-player to explain:

The headaches come in the morning. Tylenol, half a pot of coffee, and then hope they subside by lunch. Standard procedure for most NFL veterans who have had concussions. The price of admission, really, when you play on Sundays.

Even five years ago, I would have heard the NFL's proposed 18-game schedule and said, "More football! What could possibly be bad about that?" But today, we know too much. The danger's obvious to anyone that saw the Desean Jackson hit on Sunday. On some level, football ensures destruction for the people that play it. And now we're going to play more? As Colts President Bill Polian explained the 18-game schedule:

I think that the owners, and principally the commissioner, have decided that it's the way to go, and so the debate, such as it was, is over.

"I think it's a win-win all around," said Patriots owner Bob Kraft. Indeed, NFL ratings are higher than ever, and America wants more. So an 18-game regular season looks like the next logical step. The debate, such as it should be, doesn't seem to be happening.

Literally and figuratively, football's only getting bigger. The players, the popularity, and the money that mitigates everyone's reservations. But then, with the league getting more exposure every year, the evidence becomes harder and harder to ignore. Football isn't just dangerous. It's potentially life-altering for the players. So as the NFL's growth continues, what happens?

Do we trust a billion dollar corporation to look out for the best interests of its employees? If not, does Congress step in and change the rules? Do we need a fleet of independent doctors to oversee the care of NFL players? Whose jurisdiction is it to tell millionaire players how to take care of themselves? Are we worshiping a bunch of players that are ultimately disposable?

And right now, are we paying NFL players to sterilize their brains, rendering them useless for future generations, but priceless for as long as they can make the Pro Bowl?

The answers aren't clear, but these questions aren't going away. The scale will only grow. The money will only get harder to resist. For players afraid of losing their jobs, for owners seeking an extra two games, for networks reluctant to focus to much energy dwelling on the ugliness of the most popular sport in American History.*

All the while, the game gets bigger. But so does the text accompanying that asterisk.

*Pro football may cause serious, life-changing head injuries. We don't know what the effects are, and we don't know how to solve the problem.

The bigger the NFL gets—bigger and faster players, more highlights, 18 games—the more unforgivable that asterisk becomes. The NFL's greatest asset is its greatest enemy here. We all see the hits, we all see the famous, punched-out veterans losing sanity in retirement. If it's not Ted Johnson, it's Junior Seau. And for now, we can look past it all. Desean Jackson's severe concussion will subside, and he'll be back soon. In the meantime, we'll watch Jeremy Maclin.

But what happens when someday, somebody dies playing the most popular sport in American history?