Considering that the square game is only one of the five or ten varieties of the game of marbles, it is almost alarming in face of the complexity of rules and procedure in the square game, to think of what a child of twelve has to store away in his memory. These rules, with their overlapping and their exceptions, are at least as complex as the current rules of spelling. It is somewhat humiliating, in this connection, to see how heavily traditional education sets about the task of making spelling enter into brains that assimilate with such ease the mnemonic contents of the game of marbles. But then, memory is dependent upon activity, and a real activity presupposes interest.

Ch. 1 : The Rules of the Game - The Moral Judgment of the Child (1932)