A circular argument is a style of fallacious logic which assumes the truth of its conclusion beforehand, in order to establish the truth of that conclusion. Which is to say, it is self-validating. A circular argument is easy to refute.
A spherical argument is an ecology of interwoven circular arguments that cross-reference and cross-validate each other with no reference beyond the conceptual space which their activity generates. A spherical argument is vastly more complicated than a circular argument, which makes it vastly more difficult to refute.
A system of cultural logic may be considered a spherical argument, and a spherical argument may be considered a paradigm. So at the heart of a culture, a cultural paradigm is embedded. And to refute a cultural paradigm is as difficult as to refute any other spherical argument, if not more so.
Feminism is a spherical argument which has gained the status of a cultural paradigm. That is what makes it so formidable.