Dichotomism
From Categorism.com
To be stuck in black and white thinking where everything is either-or rather than sliding scales, and where concepts are tyrants of the mind. Mental cages, rather than tools for understanding. Dichotomism includes the use of “false dichotomies”, but also include over- reliance on dichotomies that are not in themselves false. Can be used as a facet or abstraction of categorism. (In Swedish: dikotomism)