Perhaps the biggest educational problem in the modern world, especially in metropolitan areas, is that man grows up in an environment almost devoid of immediate concerns and needs, which greatly impairs his perception. Prehistoric man, for example, was forced to be aware of constant threats, to plan for the future to prevent bad weather, knowing that neglect could be fatal. If he ate, he knew very well where his food came from, and he also knew what he had to do today to eat tomorrow. As for modern man, the immense facilities that surround him are not accompanied by the notion of the monstrous difficulty of making them accessible. And so he grows up with a deceptive sense of comfort, taking reality for granted, without the collaboration of his environment to show him how things work.