Joachim Pissarro: The notion of the orb is very important to you around the point of 1959.
Robert Indiana: Yes, and it relates to love, of course. It had to do with the fact that I was very briefly, and not extensively, exposed to Christian Science. . . . The one thing that impressed me that I learned in Christian Science was what the circle represented: life eternal. So it all started with that. Obviously I was obsessed at that time with what I call orbs.
Pissarro: So, you do make a distinction within the series between orbs and circles?
Indiana: Positively.
Pissarro: Orbs are full, circles are empty . . .?
Indiana: Orbs lend themselves to a sculptural concept whereas circles tend to be not so sculptural.
“Joachim Pissarro Interviews Robert Indiana,” in Joachim Pissarro and Maria Hoberman, Robert Indiana – Rare Works from 1959 on Coenties Slip (Zurich: Galerie Gmurzynska, 2011), pp. 60–61.