Describe symbolism in The Power Broker: Robert Moses and the Fall of New York by Robert Caro

The author does not use symbolism in his writing, but he does allude to the symbols that Moses created.

"In politics, power vacuums are always filled. And the power vacuum in parks was filled by Robert Moses. The old park men saw beauty in their parks. Moses saw beauty there, too, but he also saw power, say it lying there in those parks unwanted. And he picked it up - and turned it as a weapon on those who had not thought it important and destroyed them with it. Whether or not he so intended, he turned parks, the symbol of man's quest for serenity and peace, into a source of power"