Set the children free. Let them have fair play. Let them run out when it is raining, take off their shoes when they find pools of water, and when the grass of the meadows is damp with dew, let them run about with bare feet and trample on it. Let them rest quietly when the tree invites them to sleep in its shade. Let them shout and laugh when the sun wakes them up in the morning, as it wakes every other living creature.
– Maria Montessori, The Discovery of the Child (1948)