Love is a river not a lake. It has a need to spill out; a form of catharsis — children are.
When man and woman are at their highest the natural outgrowth of their love is the family; we have absolute values in Math for similar reasons.
If you have enough for each other and no more, you may not have enough to last the journey. A seed has food enough for a seedling; for a tree you’ll need to send up a shoot and send down roots.
Have you seen Cuarons Children of Men? Children are our echo; if an alien race finds us it won’t be because of Elon Musk it will be because some chic got knocked up! Imagine that!
To preserve anything without the need to repeatedly strangle life from naturally bursting forth it must be embalmed. Who wants a love that’s entombed?
Problems in marriage are exogenous to children.
If you reach up higher still you’ll find there’s always mountain to climb!
A child is the longest sustained note in the symphony of humanity!