There is something very primeval about our collective reaction to an incident of spitting.
Perhaps it is just the aesthetic of a yellowy, stringy globule of spit hurtling towards an unguarded face like a dirty great meteorite destined to spoil a virgin planet.
Maybe it's an evolutionary instinct - a deep, primal fear of the disease that lurks in the spongy, warm recesses of the lungs and trachea.
Or in a strictly football context, perhaps our repulsion is conditioned by the memory of a cloudy ball of Frank Rijkaard's phlegm hanging off the lank mullet of Rudi Voeller in 1990 like some kind of nightmarish Christmas tree decoration.
Whatever the reason, we don't like spitting much. This much can be ascertained by the fact that if you were reading the last few paragraphs while having your breakfast, there's every chance you felt a bit ill. Apologies, Early Doors can have that effect sometimes.
On Sunday, we witnessed a recurrence of this thoroughly distasteful behaviour when West Brom defender Goran Popov was sent off for spitting at Tottenham's Kyle Walker. For a decidedly uncontroversial club, the Baggies have suddenly acquired a nasty habit for attracting negative headlines.
If Peter Odemwingie's ill-advised and unauthorised road trip to London on transfer deadline day was tremendous farce, more serious fare was to come on Sunday. And the first man to leap to Popov's defence following this reprehensible act? Odemwingie, who took to Twitter to issue statements on behalf of the disgraced defender, or, as he called him, Popov the Albion man. Perhaps he had just had too much spinach that morning.
To be honest, though, no defence could save Popov after he committed football's very worst crime.
As we all know, the nausea and disgust the act of spitting provokes ensures it is described as the 'worst thing a player can do on the pitch'. Aside from snapping someone's leg in half, racially abusing them, refusing to celebrate against a former club and, apparently, the inflammatory act of just being Luis Suarez, this is true. It is a pretty nasty business.
To call as Alan Shearer has done for a six-match ban might be overdoing it, but perhaps the FA should release a definitive sliding scale of scumbaggery to let us know how deeply to channel our outrage. ED guesses spitting would land somewhere in-between kicking a ball boy and calling someone a FBC - so maybe a three-and-a-half-match ban then.
To describe spitting as the worst thing a player can do is the first instinctive reaction to a bout of gobbing. The second is to declare - as ED's house-mate did with perfect timing on Sunday - that you'd rather be punched in the face than be spat at. To which ED would reply: who is doing the punching?
Are we talking a Mike Tyson power punch, or something more akin to Michael 'the baddest man on the planet' Owen's attempted haymaker on Mikel Arteta at the Emirates on Saturday?
Thankfully, incidents of projectile spittle are rare - especially now El Hadji Diouf appears to have removed it from his own personal repertoire - and West Brom manager Steve Clarke was quick to condemn Popov's behaviour.
"The game changed with the sending off," he said. "I'm absolutely disgusted with Goran's behaviour. One of the group has let the players down. There's no excuse for that. There's no place for it in life, never mind on a football pitch.
"I haven't had a one-on-one discussion with Goran, we spoke about it after the game as a group. I would like to think that at some stage he will apologise."
Popov will also be fined two weeks' wages for his misdirected phlegm projectile, joining Odemwingie on the naughtiest of naughty steps at West Brom. The only way it could get naughtier would be for Danny Dyer to turn up looking for a bit of trouble.
But while the utterly surreal nature of Odemwingie's transgression means his notoriety is unlikely to fade at any immediate stage - on Saturday, Norwich fans chanted at QPR, "Odemwingie, he would have scored that"; on Sunday, Spurs fans chanted at West Brom, "Odemwingie, he would have scored that" - Popov has hope of rehabilitation.
Spitting is nasty stuff, but you take your punishment and get on with things. Patrick Vieira did so after spitting at Neil Ruddock and Antolin Alcaraz did so after gobbing at Richard Stearman.
Despite claims to the contrary there are bigger problems in football: at least spitting is one that we can all agree is beyond the pale and move on.
Still, it did rather top off what Clarke rather optimistically described as merely a "difficult week for us".
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QUOTE OF THE DAY: “I don’t think it is finished. There is room for mistakes. I think we probably need to win all of our games but that can happen sometimes. If we don’t win all then we probably need to win 11 or 12 if we are to have a chance. But the championship is not over, absolutely not, because of last season and also what happened two years ago. Then, Chelsea were nine points behind and they were only two points behind when they went to United in the final week of the season. It’s a long way to the end. No, it’s not over. This result doesn’t change anything. We can recover nine points.” - Manchester City boss Roberto Mancini keeps talking a good game after drawing at home to Liverpool on Sunday.
FOREIGN VIEW: “I was supposed to be on the bench, but then Pazzo hurt himself so I played instead. I’m happy it turned out like that, as I put in a good performance. We are strong in attack, even if I haven’t played much and feel my legs are heavy. I must work to improve my fitness levels. It is a good start, but now I must continue scoring goals. We created a great deal this evening, but Daniele Padelli performed some good saves. We deserved to win and in the end we did it.” - Mario Balotelli gets his AC Milan career off to a flying start with both goals in a 2-1 win over Udinese, the second of which was an injury-time penalty.
COMING UP: We bring you our Premier League and European Teams of the Week as well as checking in with Jan Molby and the chaps at Pitchside Europe for the latest from Ligue 1.