Taxonomy of meanings for 是故:  

  • THUS
    • PPadS1.postS2thus, and along these linesVK
  • THEREFORE
    • PPadS1.postS2objective reasonthis being so; for this objective reason: therefore
    • PPadS1.postS2subjectivethis being the motivation for this subjective reason: therefore (non-narrative)
    • PPadV{PRED}.postN{SUBJ}parenthetic: this being so; therefore