Related:

• You [humans] are, after all, essentially irrational. -- Spock, "Metamorphosis," stardate 3220.3
• Valeris: "Captain, may I remind you that regulations specify thrusters only while in Spacedock?
  Uhura: ["Tsk, tsk."] Spock: [Clears throat] McCoy...
• You humans have that emotional need to express gratitude.
  You're welcome," I believe, is the correct response....
• What is it in you humans that requires an overwhelming display of emotion in a situation such as this?
  Two men pursue the only reasonable course of action indicated, and yet you feel that something else is necessary....
• Kirk: "You are about to remind me that logic alone dictates your actions?
  Spock: "I would not remind you of that which you know so well....
• You [humans] find it easier to understand the death of one than the death of a million.
  -- Spock, "The Immunity Syndrome," stardate 4307.1...
• Kirk: "Mister Spock, do you know anyone on this ship who even remotely resembles Satan?
  -- "The Apple", Stardate 3715.6....
• Saavik: "Admiral, what if Reliant fails to follow us into the nebula?
  Spock: "I think we can guarantee that she'll follow us, Lieutenant....
• Humans smile with so little provocation. -- Spock, "Journey to Babel," stardate 3842.3.