Preservation And Extermination

Rex: Donate? Donate!?! 
K-9: It's what humans do.
Rex: Daleks exterminate! Daleks do not donate!
K-9: You can't always exterminate. Sometimes, it's important to preserve.
Rex: Exterminate and preserve? The two concepts are mutually exclusive!
K-9: Illogical. Everyone preserves what they need, and exterminates everything else.
Rex: What? You mean everyone exterminates?
K-9: Correct. Daleks just talk about it all the time, that's all.
Rex: Are you saying Daleks are windbags?
K-9: Incorrect. Daleks are full of much more than hot air.
Rex: I'd exterminate you if you'd ever let me win an argument.
K-9: You see! As you never can, you must preserve, preserve, Preserve Me!