You have just imagined-with allowances for the kind of oversimplifications that seem to keep journalists from winning the foundation's famous "genius grants"-the job of Adele Smith Simmons, the president of Chicago's huge and seemingly ubiquitous John D. and Catherine T. MacArthur Foundation. From the so-called genius grants (actually, the MacArthur Fellowships) to the preponderance of educational videos in your local library to the sponsorship of programs on National Public Radio, the MacArthur has made itself into a public presence in a way that is unique among its older, more established colleagues in the world of dispensing the interest earned on huge fortunes.