American science, long a source of national power and pride, is increasingly becoming a private enterprise. In Washington, budget cuts have left the nation's research complex reeling. Labs are closing. Scientists are being laid off. Projects are being put on the shelf, especially in the risky, freewheeling realm of basic research. Yet from Silicon Valley to Wall Street, science philanthropy is hot, as many of the richest Americans seek to reinvent themselves as patrons of social progress through science research. The result is a new calculus of influence and priorities that the scientific community views with a mix of gratitude and trepidation. For better or worse," said Steven A. Edwards, a policy analyst at the American Association for the Advancement of Science, "the practice of science in the 21st century is becoming shaped less by national priorities or by peer-review groups and more by the particular preferences of individuals with huge amounts of money." This is philanthropy in the age of the new economy - financed with its outsize riches, practiced according to its individualistic, entrepreneurial creed. Yet that personal setting of priorities is precisely what troubles some in the science establishment. Many of the patrons, they say, are ignoring basic research - the kind that investigates the riddles of nature and has produced centuries of breakthroughs, even whole industries - for a jumble of popular, feel-good fields.