He was quite the accomplished artist and intellectual. His series, Atheism: A Rough History of Disbelief is well worth watching. Miller was also part of Beyond the Fringe with Dudley Moore, Peter Cook, and Alan Bennett. They even put in a 1962 appearance on What's My Line?, as Beyond the Fringe was a Broadway sensation at the time.
Miller was a noted director of operas, a physician, and probably anything else he wanted to be.