“An armed society is a polite society. Manners are good when one may have to back up his acts with his life.”
Other Robert A. Heinlein Quotes
For me, politeness is a sine qua non of civilization.
Robert A. Heinlein 
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Anyone who considers protocol unimportant has never dealt with a cat.
Robert A. Heinlein
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No statement should be believed because it is made by an authority.
Robert A. Heinlein
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Be wary of strong drink. It can make you shoot at tax collectors... and miss.
Robert A. Heinlein
55% of people like this quote