Geston was born in the family of two teachers in Atlantic City, New Jersey. He graduated from Abington High School and then, in 1968, from Kenyon College in Ohio with a degree in history. He received his law degree from New York University Law School in 1971. His first science fiction novel, Lords of the Starship, written when he was 20 and still in college, was widely praised when it was published in 1967. He has published relatively little since the mid-1970s and is a full time attorney.