Abstract
This memorandum, originally written in 1961 and published in an obscure journal in 1986, emphasizes the degree to which general acceptance has been substituted for proof in current scientific practice. Its main objective is to reveal which generally accepted ideas have no sound factual basis and therefore _could_ be erroneous. The new and improved basic theory that is fervently desired must conflict with some items of this kind, and probably with many of them. Such conflicts, if confined to the categories herein enumerated, do not constitute valid arguments against any new theory that may be proposed, and should not be allowed to block consideration of new theories.