"... there is Brouwer's , which is utterly destructive in its results. The whole theory of the \,\aleph\,'s greater than \,\aleph_1\, is rejected as meaningless (Brouwer 1907, 569). Cantor's conjecture itself receives several different meanings, all of which, though very interesting in themselves, are quite different from the original problem. They lead partly to affirmative, partly to negative answers (Brouwer, 1907, I: 9; III: 2). Not everything in this field, however, has been sufficiently clarified. The “semi-intuitionistic” standpoint along the lines of H. Poincaré and H. Weyl ... would hardly preserve substantially more of set theory."