Quintilian's observation on the smacking of children
Source: Institutes of Oratory, Rome, circa 88 CE

"I disapprove of flogging, although it is the regular custom... because in the first place it is a disgraceful form of punishment and fit only for slaves, and is in any case an insult, as you will realize if you imagine its infliction at a later age. Secondly if a boy is so insensible to instruction that reproof is useless, he will, like the worst type of slave, merely become hardened to blows... And though you may compel a child with blows, what are you to do with him when he is a young man no longer amenable to such threats and confronted with tasks of far greater difficulty? Moreover when children are beaten, pain or fear frequently have results of which it is not pleasant to speak and which are likely subsequently to be a source of shame, a shame which unnerves and depresses the mind and leads the child to shun and loathe the light....I will not linger on this subject; it is more than enough if I have made my meaning clear. I will content myself with saying that children are helpless and easily victimized, and that therefore no one should be given unlimited power over them."

This was written about the same time as the Gospel of Mark.