Living: The Collectors: Three Vignettes

People buy art for all reasons and with all incomes. Broadly, however, they fall into three categories: the amateur, who appreciates beautiful objects for their own sake; the investor, who is primarily intent on making money; and the rare great collector, who assembles treasures on the grand scale that enriches society. Three vignettes:

The Addicted Amateur With gray-black locks dangling in ringlets over his black velvet jacket, Stuart Pivar, 49, resembles an apparition from one of the dark Victorian paintings of which he is an avid collector. A New Yorker who owns several plastics...