 Yet I do not say that all those who are included under the name of Academic have upheld the rule of modesty, since even its basic creed is in dispute and parts of it are open as much to derision as to error… If the Academic is in doubt about each thing, he is certain about nothing… But he possesses uncertainty about whether he is in doubt, so long as he does not know for certain that he does not know this doubt itself. (PC: 150)