"Locke makes the very good point that 'most children’s constitutions are either spoiled, or at least harmed, by cockering and tenderness.'"

"That lovely seventeenth century word ‘cockering’ means ‘to indulge or spoil.' Locke goes on to recommend that children are not too warmly wrapped up in winter, in order that they learn to endure the cold, in the manner of the Spartans. He also reckons that the shoes of children should be made deliberately leaky in order to toughen up the feet. Certainly my third son Henry, more ignored than the other two, has tough feet, and spent whole summers shoeless. Henry maintained when nine years old that ‘shoes were prisons for the feet.'... Our youngest, Henry, was born in the house with two lovely midwives, and he has grown into a solid, healthy lad. He spent his first eight years roaming the fields and rocky coves, and even from an early age he was a fast runner and a confident climber.... Henry would disappear for hours with his friend Gilbert doing God knows what in the fields. The key here was lack of parental supervision. When parents supervise, they are at some level imposing their own ideology or fantasy of country life or wild life on to their children. That’s why I have always recoiled from those adventure holidays and back-to-nature holidays for children. children. There is some damn theory or other underpinning the whole thing, like a Steineresque philosophy. They remind me of the Hitler Youth. This is what D. H. Lawrence is getting at when he says that children should be left with a lazy woman who can’t be bothered with them. Leave them alone!"

From "Why Ignoring Your Children Will Make Everyone Happier: Or, What to Neglect When You're Neglecting," Tom Hodgkinson.

Locke is the philosopher John Locke. The quote is from "Some Thoughts Concerning Education" (1690).

"Cockering" — do you like that word? Can you use it? Maybe not. The OED calls it "Now English regional."  The historical examples include this from the King James version of the Bible (1611): "Cocker thy childe, and hee shall make thee afraid." And let me give you this quote too:

1682 T. Shadwell Lancashire-witches i. 7 Dost thou think, because thy foolish Mother has Cocker d thee with morning Cawdles and afternoons Luncheons, thou art fit to make Love?

I presumed that "cawdle" was an old spelling of "cuddle," but no, it's an alternative spelling of "caudle," which is "A warm drink consisting of thin gruel, mixed with wine or ale, sweetened and spiced, given chiefly to sick people."

As for "Steineresque philosophy," there's nothing else in the book about it. I googled and guess it refers to this person — Rudolf Steiner — whose ideas are listed as "Anthroposophy, anthroposophical medicine, biodynamic agriculture, eurythmy, spiritual science, Waldorf education, holism in science."  He died in 1925 and wasn't connected to the Hitler Youth. Indeed: "In 1921, Adolf Hitler attacked Steiner on many fronts, including accusations that he was a tool of the Jews... In 1922 a lecture Steiner was giving in Munich was disrupted when stink bombs were let off and the lights switched out, while people rushed the stage apparently attempting to attack Steiner, who exited safely through a back door.... The 1923 Beer Hall Putsch in Munich led Steiner to give up his residence in Berlin..."