"Money is the string with which a sardonic destiny directs the motions of its puppets"

The quote by W. Somerset Maugham recommends that money is a powerful force and device that can regulate individuals's actions and also decisions. The expression "sardonic fate" implies that fate or possibility might have a twisted or ironic sense of humor, and that it is using cash to manipulate individuals for its own enjoyment. Using words "creatures" recommends that those that are encouraged entirely by cash are not in control of their very own lives, and are basically being controlled by outdoors pressures. It is a commentary on exactly how people's obsession with riches can lead them down a course of self-destruction and moral corruption.