He was extremely terse.

In Los Angeles, on La Cienega Boulevard, Phil Leider sat in an office above my head from '64 to '67 while I ran the Ferus Gallery. I can distinctly remember one day when my skin color changed as a result of the charge he always radiated. He adored dialogue and would rab the lapels of anyone around and go to it. He played a significant role in laying the ground on which much contemporary art and criticism is based. He was for me and compass to get you to that clearing in the murky art world.