All 3 Uses of

metaphysical
in
Moby Dick

Should you ever be athirst in the great American desert, try this experiment, if your caravan happen to be supplied with a metaphysical professor.†
Chpt 1-3 *

metaphysical = relating to questions that cannot be answered with the scientific method

Well, then, however the old sea-captains may order me about—however they may thump and punch me about, I have the satisfaction of knowing that it is all right; that everybody else is one way or other served in much the same way—either in a physical or metaphysical point of view, that is; and so the universal thump is passed round, and all hands should rub each other's shoulder-blades, and be content.†
Chpt 1-3

So strongly and metaphysically did I conceive of my situation then, that while earnestly watching his motions, I seemed distinctly to perceive that my own individuality was now merged in a joint stock company of two; that my free will had received a mortal wound; and that another's mistake or misfortune might plunge innocent me into unmerited disaster and death.†
Chpt 70-72

metaphysically = in a manner that relates to questions that cannot be answered with the scientific method

Definitions:

(1) (metaphysical)
relating to beliefs not proven with the scientific method

or:

without material form or substance

or:

highly abstract and overly theoretical

or:

relating to metaphysics (the philosophical study of being and knowing)
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

More rarely, metaphysical can reference a 17th-century style of British poetry.