Their first attempt.

I knew a pair of parents.  I am convinced, in spite of all that can be said to the contrary, they were fond of their Child; it was their first.  They were anxious to do the right thing.  They read with avidity all books and articles written on the subject of Children.  They read that a Child should always sleep lying on its back, and took it in turns to sit awake o’ nights to make sure that the Child was always right side up.

But another magazine told them that Children allowed to sleep lying on their backs grew up to be idiots.  They were sad they had not read of this before, and started the Child on its right side.  The Child, on the contrary, appeared to have a predilection for the left, the result being that neither the parents nor the baby itself for the next three weeks got any sleep worth speaking of.

Later on, by good fortune, they came across a treatise that said a Child should always be allowed to choose its own position while sleeping, and their friends persuaded them to stop at that—told them they would never strike a better article if they searched the whole British Museum Library.  It troubled them to find that Child sometimes sleeping curled up with its toe in its mouth, and sometimes flat on its stomach with its head underneath the pillow.  But its health and temper were decidedly improved.