McCoy was usually the one making the emotional appeal to the captain for the audience's sake. And humans in general were the emotional ones. However, Kirk was

McCoy was usually the one making the emotional appeal to the captain for the audience's sake. And humans in general were the emotional ones. However, Kirk was supposed to be the moderate one that didn't give-way to pure logic or emotion and find the best solution somewhere in between. Which was the moral of the story of the week.