Okay this is one of my favorite relationships of the show but I have seen so many people completely not understand it. Granted I think this interpretation is in the minority but I have seen it enough... 1) Spock and McCoy don't like each other. Okay yes I know Spock and McCoy argue all the time. That is part of their relationship. It wasn't something that started out with these characters. It just became popular and the writers caught on to that and continued to write for it. However despite their disagreements (and yes they weren't always playful) it is abundantly clear that Spock and McCoy actually respect and like each other. Spock and McCoy both have helped each other countless times. Spock entrusted his soul to McCoy. Both Spock and McCoy have shown worry when the other was hurt, etc. Really Spock and McCoy must be the absolute worst enemies ever. But of course if that doesn't convince you both Nimoy and De Kelley have said that Spock and McCoy liked each other deep down. Heck even Roddenberry has said it (there are plenty of quotes available which I will add later). 2) McCoy is racist against Spock I am sorry but this is just silly. I think people who care so much about supposed racism against aliens should maybe be concerned with real racism but anyways... Yes I realize that McCoy did often call out Spock's Vulcan features and green blood but these lines were obviously meant to be funny. If you don't find them funny what can I say, this was written in the 1960's. Heck just as a real life example please watch Match Game in the 1970's . This was an extremely "liberal show" at the time. And I know for a fact than many of the panelists were involved in the civil right moments. But there were tons of jokes during the show that would definitely be considered politically incorrect today if not far worse than anything McCoy said about Spock. Times change and so is what is considered acceptable. But really if you think McCoy (one of the 3 main heroes) was meant to be racist when Gene Roddenberry was upset when a minor character might be a drug dealer on the enterprise in City on the Edge of Forever you must be kidding yourself. On another note Kirk called out characters when he felt they were being racist against Spock. Notice how he never calls out McCoy. He usually just laughs because he knows in the end the Spock/McCoy banter is harmless. And no I don't think it is because McCoy is his friend. Sure McCoy could get away with a lot, but Kirk would tell him off when he went too far. Another thing I don't understand why some people always blame McCoy when Spock had his own nasty judgements about humans and McCoy. I love Spock but he wasn't without faults himself. 3) All Our Yesterdays This seems to be the one episode that Spock/McCoy haters cling to to prove that Spock doesn't like McCoy or the things he says about him. Yes I know one line in one episode from the inconsistent 3rd season proves a lot. This isn't even written by one of the series regulars. Now I am not saying All Our Yesterdays is a bad episode. I actually enjoy the Spock/McCoy scenes in this one. But this is an episode where the writer has Spock fall in love & only after Nimoy protested that Spock would never just do this that they write in the line of Spock regressing to his Vulcan ancestry. For some reason I don't think it is the best episode to judge Spock's feelings about McCoy. This wasn't the normal Spock, which McCoy quickly realized. If anything I would say Spock likes arguing & debating with McCoy. Whenever McCoy says something, Spock is quick to zing one back. Really he is definitely never shown to be helpless against McCoy. And yes at times I am sure both McCoy and Spock are annoyed by each other, I also think deep down they enjoy those verbal sparring matches.