What is to take the place of the soul and life-destroying metaphysics inherited from the nineteenth century? The task of our generation, I have no doubt, is one of metaphysical reconstruction. It is not as if we have to invent anything new; at the same time, it is not good enough merely to revert to the old formulations. Our task—and the task of all education—is to understand the present world, the world in which we live and make our choices.
The problems of education are merely reflections of the deepest problems of our age. They cannot be solved by organisation, administration, or the expenditure of money, even though the importance of all these is not denied. We are suffering from a metaphysical disease, and the cure must therefore be metaphysical. Education which fails to clarify our central convictions is mere training or indulgence. For it is our central convictions that are in disorder, and, as long as the present anti-metaphysical temper persists, the disorder will grow worse. Education, far from ranking as man's greatest resource, will then be an agent of destruction, in accordance with the principle corruptio optimi pessima.
— small-is-beautifulp. 28–30
corruptio optimi pessima - also a phrase adopted by Illich.