Wilson’s renormalization group : a paradigmatic shift

A personal and subjective recollection, concerning mainly Wilson’s lectures delivered over the spring of 1972 at Princeton University (summary of a talk at Cornell University on November 16, 2013 at the occasion of the memorial Kenneth G. Wilson conference). 1 Why was it so difficult to accept Wilson’s viewpoint? In 1971-72 I was on leave from Saclay, employed by the theory group at the physics department of Princeton University. My background at the time was mainly field theory. Just before this I had been working with C. Itzykson on the use of classical approximations in QED, dealing with problems such as pair creation by an oscillating electromagnetic field , but I was aware that the understanding of the intriguing features of scaling laws and universality near a critical point was a difficult non-perturbative problem. Ken Wilson was invited in the fall of 1971 to give a talk on his recently published articles