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..."