From John Rock's 1963 book, The Time Has Come, which was part of his determined effort to persuade the public and the Vatican, that the Pill was a natural and acceptable form of birth control.
"Because of the enhancement of our basic animal sex-nature by its integration with our spirituality, human sexual relations without love becomes inadequate for full satisfaction, and love without coitus at mutually agreeable intervals becomes frustrating and ultimately demoralizing. Love fused by coitus, but without children to bring up, lacks completion; but when it brings more children than can be properly cared for, it is dangerously strained, even distorted.
Such is what, after forty years as a Catholic obstetrician-gynecologist, student and teacher, I have found to be the nature of human sexuality. And from this derives what I feel is right and wrong in the matter of birth control…to those whose uncontrolled reproductivity would destroy the balance between the components of their sexuality (coital urge, love of mate and love of young) there should be available suppressive means and methods appropriate to their particular capabilities and conditions – religious, social, educational, and so forth."
The Time Has Come: A Catholic Doctor's Proposals to End the Battle Over Birth Control, by John Rock (Knopf, 1963)