Each child is biologically required to have a mother. Fatherhood is a well-regarded theory, but motherhood is a fact.
P. J. O'Rourke
P. J. O'Rourke
I take his quote to mean that motherhood is more difficult than fatherhood, especially back in the time he was active. The quote should, I feel, not be observed as a factual statement, but rather in the vein of his politically based humor. Largely, it was a simpler time.