所以然 suǒyǐrán the why and wherefore Definitions Defs Origin Strokes Stroke Words Sentences Sents 知其然而不知其所以然 zhīqírán'érbùzhīqísuǒyǐrán to know the result but not the cause A saying meaning to know that something is the case without knowing why it is so; to understand the what but not the why.