In Part 2 of his book Discourse on Method, he elaborated both his traditional and modern attitude towards education. He explained that since mathematics has achieved the certainty for which human thinkers seek, the traditional persons should rightly turn to mathematical reasoning as a model for progress in human knowledge. Expressing perfect confidence in the capacity of human reason to achieve knowledge, Descartes proposed an intellectual process that suggested the architectural destruction and rebuilding of an entire town. In Part 2, he writes:
It is true, however, that it is not customary to pull down all the houses of a town with the single design of rebuilding them differently, and thereby rendering the streets more handsome; but it often happens that a private individual takes down his own with the view of erecting it anew, and that people are even sometimes constrained to this when their houses are in danger of falling from age, or when the foundations are insecure.
What is true of buildings and constitutions is also true for knowledge. The fact that the existing sciences have often grown up gradually with no uniform plan explains this as a key role of processing the "unlearning" of what we have previously learned. ...