Laudator Temporis Acti

The gospel for last Sunday (Laetare Sunday) was from John, chapter 9, which starts thus:

And as Jesus passed by, he saw a man which was blind from his birth. And his disciples asked him, saying, Master, who did sin, this man, or his parents, that he was born blind? Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him.

Some argued that sin was possible even before birth, e.g. Sanhedrin 91a (tr. H. Freedman):

Antoninus also enquired of Rabbi, 'From what time does the Evil Tempter hold sway over man; from the formation [of the embryo], or from [its] issuing forth [into the light of the world]? — 'From the formation,' he replied. 'If so,' he objected, 'it would rebel in its mother's womb and go forth. But it is from when it issues.' Rabbi said: This thing Antoninus taught me, and Scripture supports him, for it is said, At the door [i.e.,where the babe emerges] sin lieth in wait.

The reference is to Genesis 4.7 (sin lieth at the door).

Exodus 20.5 is the locus classicus for the idea that a parent's sin could cause sickness or deformity in a child:

I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me.

Aristotle, Nicomachean Ethics 3.5.15 (tr. H. Rackham), rejected the idea that a man born blind was guilty:

Nobody would reproach, but rather pity, a person blind from birth, or owing to disease or accident, yet all would blame one who had lost his sight from tippling or debauchery.

Jesus pitied the man who was blind from birth, and healed him.