Philosophical -ism formed by 怀疑 (to doubt) + 论 (doctrine/theory). The 论 suffix turns concepts into named -isms: 唯物论 (materialism), 进化论 (theory of evolution), 不可知论 (agnosticism). A 怀疑论者 is a 'skeptic'.
culture
In Chinese philosophy curricula 怀疑论 typically refers to ancient Greek Pyrrhonian skepticism, Cartesian methodical doubt 笛卡尔, and Hume 休谟. In journalism it's commonly applied to climate skeptics and vaccine skeptics.
