But the beautiful thing about this episode is that it gives us something that enriches Vulcans, makes them more than a one-note alien species. Spock himself emphasizes that the ritual is anything but logical. It's a holdover from the barbaric Vulcan past that we'd only heard lip service to prior to this episode. It demonstrates many things about the Vulcan culture...that they're proud of tradition even when it predates Surak, that they really are violent savages underneath their logical fašade, and possibly the reason that they don't find a more logical way of dealing with their mating cycle is because it is in such stark contrast to everything that they like to think they've become. We're pretty illogical about sex in this culture...everyone enjoys it and we base our lives around obtaining it, but you can show gruesome murders on TV before boobies.
The way I view it, Spock knew there was a possibility of a challenge which would lead to a fight to the death. He invited down his off world captain and doctor without telling them this information.
Spock wasn't exactly his proper self this episode. And he was genuinely surprised when T'Pring halted the ceremony...just go back and look at his reaction.
A beaker full of death wrote:
The possibility was so remote as to not be worth mentioning. When you chose your best man, did you really expect him to marry your wife if you didn't show up?
Wait, was that actually an old custom and not just part of a Seinfeld routine...?