Joseph Epstein takes on that most enchanting (and, alas, increasingly rare) of human gifts, charm. Almost everyone will recognize when he or she is in the presence of charm, he writes. Charm is magic of a kind; it casts a spell. In the presence of charm the world seems lighter and lovelier. A charming person can cause you to forget your problems, at least temporarily, to hold the world's dreariness at bay. Charm is a reminder that the world is filled with jolly prospects and delightful possibilities. Watching Fred Astaire dance, or listening to Blossom Dearie sing, or reading the poems of C.P. Cavafy, or merely looking at Rita Hayworth or Ava Gardner, one recalls that the world can be a pretty damn fine place.