1
general::
Phrase(s): *method in one’s madness
Fig. a purpose in what one is doing, even though it seems to be crazy. (*Typically: be ~; have ~.) • What I’m doing may look strange, but there is method in my madness. • Wait until she finishes; then you’ll see that she has method in her madness.
McGrawhill's American Idioms And Phrasal Verbs