Star Trek: The Original Series, Season 2

[Amanda Grayson appeals to Spock about undergoing a blood transfusion to save his father, Sarek, but Spock is too stubborn and harps on about being a Vulcan]

Spock:
It means to adopt a philosophy, a way of life, which is logical and beneficial. We cannot disregard that philosophy merely for personal gain, no matter how important that gain might be.

Amanda Grayson:
When you were five years old and came home stiff-lipped, anguished, because the other boys tormented you, saying that you weren't really Vulcan, I watched you knowing that, inside... that the human part of you was crying, and I cried, too. There must be some part of me in you, some part that I still can reach. If being Vulcan is more important to you, then you'll stand there speaking rules and regulations from Starfleet and Vulcan philosophy and... and let your father die, and... then I'll hate you for the rest of my life.

Spock:
Mother...

Amanda:
Oh, go to him. Now. Please.

Spock:
I cannot. [gets slapped by Amanda, who leaves the room]