meth·od / ˈme[unvoicedth]əd/ • n. (often method for/of) a particular form of procedure for accomplishing or approaching something, esp. a systematic or established one: a method for software maintenance labor-intensive production methods. ∎  orderliness of thought or behavior; systematic planning or action: historical study is the rigorous combination of knowledge and method. ∎  (often Method) short for method acting.PHRASES: there is method in one's madness there is a sensible foundation for what appears to be foolish or strange behavior.

method † systematic treatment of a disease; special form of procedure; orderly arrangement. XVI. — F. méthode or L. methodus — Gr. méthodos pursuit of knowledge, mode of investigation, f. metá META- + hodós way.
So methodical (hist.) belonging to a school of physicians (between ‘dogmatists’ and ‘empirics’); pert. to method XVI. f. late L. methodicus — Gr. methodist physician of the methodical school; one who follows a certain method XVI; member of the Holy Club established at Oxford in 1729; member of religious bodies originating in this. — modL. methodista; hence methodism XVIII.

method method acting a technique of acting in which an actor aspires to complete emotional identification with a part, based on the system evolved by Stanislavsky and brought into prominence in the US in the 1930s.
method in one's madness sense or reason in what appears to be foolish or abnormal behaviour; from Shakespeare's Hamlet (1601) in the scene in which Hamlet feigns insanity, ‘Though this be madness, yet there is method in't.’