In the retina, there are two different types of light-detecting cells: rods and cones. The rods are used for seeing in low-light conditions, and there’s only one kind of those. The cones are a different story. There are three kinds of cone cells that roughly correspond to the colors red, green and blue.
I argued that, whatever validity the military and political arguments were for an attack, America’s traditions and history would not permit such a course of action. Whatever military reasons the chiefs and others could marshal, they were nevertheless, in the last analysis, advocating a surprise attack by a very large nation against a very small one. This, I said, could not be undertaken by the US if we were to maintain our moral position at home and around the globe. Our struggle against Communism throughout the world was far more than physical survival – it had as its essence our heritage and our ideals, and these we must not destroy. – Robert Kennedy, Thirteen Days: A Memoir of the Cuban Missile Crisis ||| Thirteen Days (2000)