Definition of "metaphysician"

Now it so happened that Francis was Mrs. Clarke's favourite: whether from having seen the least of him, or from the great difference between them—two common causes of liking—or because she felt some sort of vanity in her near relationship to so very fine a gentleman, are points too curious to be decided by any but a metaphysician.

1831, L[etitia] E[lizabeth] L[andon], chapter IV, in Romance and Reality. […], volume II, London: Henry Colburn and Richard Bentley, […], page 65

PROPOSITION IV. That axiom of metaphysicians which is termed the principle of contradiction, and which affirms that it is impossible for any being to possess a quality, and at the same time not to possess it, is a consequence of the fundamental law of thought, whose expression is x2 = x.

1854, George Boole, An Investigation Of The Laws Of Thought, On Which Are Founded The Mathematical Theories Of Logic And Probabilities, Watchmaker Publishing, published 2010, §III.15, page 34

In 1928 Heidegger succeeded Husserl to take a chair at Freiburg and in his inaugural lecture made a pronouncement that earned him a reputation as an archetypal metaphysician with his claim that our awareness of people as a whole depends on our experience of dread in the face of nothingness.

2014 April 12, Michael Inwood, “Martin Heidegger: the philosopher who fell for Hitler [print version: Hitler's philosopher]”, in The Daily Telegraph (Review)‎, London, page R11