[f. THEORY (or its Gr. or L. source) + -IST.]
1. An adept in the theory (as distinct from the practice) of a subject. Often with mixture of sense 2.
1594. Carew, Huarte’s Exam. Wits, xii. (1596), 177. It is a miracle to find out a Phisition, who is both a great Theorist, and withall a great Practitioner.
1664. Power, Exp. Philos., Pref. 16. The Theorists in Conical Sections.
1784. Cook’s Voy. Pacific Ocean, V. vii. III. 144, note. Burney … perhaps the greatest musical theorist of this or any other age.
1855. Macaulay, Hist. Eng., xx. IV. 492. It is … curious … that a man who, as a theorist, was distinguished … by the largeness of his views … should, in practice, have been distinguished … by the obstinacy with which he adhered to an ancient mode of doing business.
2. One who theorizes; one who frames or propounds a theory or theories, a theoretical investigator or writer; one who holds or maintains a theory; sometimes, a framer or maintainer of a mere hypothesis or speculation (cf. THEORY1 6).
1646. Sir T. Browne, Pseud. Ep., 115. That a Brock or Badger hath his legs of one side shorter then of the other,… an opinion … received not only by theorists and unexperienced beleevers, but assented unto by most who … behold and hunt them dayly.
1692. Bentley, Boyle Lect., vii. 204. It [gravitation] is lately demonstrated … by that very excellent and divine theorist Mr. Isaac Newton.
1735. Johnson, Lobo’s Abyssinia, Descr., x. 106. Some of these Theorists have been pleas’d to declare it as their favourite Notion.
1884. Spectator, 4 Oct., 1309/1. As a theorist on law, he has a distinctive place of his own.
