I love wisdom passed down in pithy, easily regurgitated quotes. This one from Benjamin Franklin makes great use of the (often misplaced) human fear of wolves to make a political statement.
One has to wonder about the double-edged sword of these words, however. Does the advice eschew acts of kindness and generosity, thus making more wolves? We tread a fine line, in wanting not to be taken advantage of, in stead of becoming callous to the needs of others.