Star Trek: The Original Series, Season 2

Kirk:
Bones? You could stop all this by saying no. That's why I called you all here together. We'll all be deeply involved. It must be unanimous.

McCoy:
Then I'll still want one question answered to my satisfaction. Why? Not a list of possible miracles, but a simple basic understandable why that overrides all danger. And let's not kid ourselves that there is no potential danger in this!

Kirk:
They used to say that if Man was meant to fly, he'd have wings. But he did fly. He discovered he had to. Do you wish that the first Apollo mission hadn't reached the moon, or that we hadn't gone on to Mars and then to the nearest star? That's like saying you wish that you still operated with scalpels and sewed your patients up with catgut like your great-great-great-great-grandfather used to. I'm in command. I could order this. But I'm not because Doctor McCoy is right in pointing out the enormous danger potential in any contact with life and intelligence as fantastically advanced as this. But I must point out that the possibilities, the potential for knowledge and advancement is equally great. Risk...risk is our business. That's what this starship is all about. That's why we're aboard her.