So shocking and counter-intuitive were Cantor's ideas at first that the eminent French mathematician Henri Poincare condemned the theory of transfinite numbers as a 'disease' from which he was certain mathematics would someday be cured. Leopold Kronecker, one of Cantor's teachers and among the most prominent members of the German mathematics establishment, even attacked Cantor personally, calling him a scientific charlatan, a renegade and a corrupter of youth.
