Black holes power many of the most powerful sources in the universe through their disks, jets and winds. This power derives from their rotational energy (Nature) and the gravitational energy released by accreting gas (Nurture). The balance of these two modes and their implications, will be re-examined in the light of recent, remarkable observations of the nearby galaxy M87 by the Event Horizon Telescope. Implications for other sources will be discussed. Professor Blandford is hosted by Dr. Brian Reville (brian.reville@mpi-hd.mpg.de)