(1.) The chairs of theology and philosophy (during the scholastic ages) were the oracular seats from which the doctrines of Aristotle were expounded as the rationale of theological and moral truth. "There cannot be a body of rules without a rationale, and this rationale constitutes the science. There were poets before there were rules of poetical composition; but before Aristotle, or Horace, or Boileau, or Pope could write their arts of poetry and criticism, they had considered the reasons on which their precepts rested, they had conceived in their own minds a theory of the art. In like manner, there were navigators before there was an art of navigation; but before the art of navigation could teach the methods of finding the ship's place by observations of the heavenly bodies, the science of astronomy must have explained the system of the world." Anthony Sparrow, bishop of Exeter. is the author of a work entitled A Rationale upon the Book of Common Prayer.
(2.) A peculiar form of the bishop's pallium (pectorale, λογύον), appropriated by the bishops of Rome to themselves from the time in which they began to assume the title of pontifices maximi and the dignity of the high-priests of the Old Testament. It was sometimes sent by the Roman pontiffs to other bishops as a mark of distinction and favor. It was in the form of a trefoil, quatrefoil, or oblong square, like the piece of stuff worn by the Aaronic high-priest. It appears in England on bishop Gifford's monument at Worcester in 1301. It was worn, perhaps for the last time on record, at Rheims. The pope has a formal, and cardinals and Italian bishops wear superb brooches to clasp their copes. The Greek περιστέθιον, worn by patriarchs and metropolitans over the chasuble, is an oblong plate of gold or silver, jewelled.
(3.) The word rationale is also the name of a treatise explaining the meaning, and justifying the continuance, of that ceremonial which it was thought fit to retain in the Church of England in the year 1541. The members of the committee to whom this subject was intrusted were warmly attached to the splendor of the Roman ritual, and, of course, made few alterations. The collects in which prayers were offered for the pope, and the offices for Thomas a Becket and some other saints, were omitted; but so slight were the changes introduced that in many churches the missal and breviary already in use were retained. The Rationale Divinorum Officiorum of Durand, bishop of Mende, written in the latter part of the 13th century, gives the "reasons" of the forms and ceremonies of Romish worship. See Collier, Eccles. Hist. v, 106; Burnet, Hist. of the Ref. 1, 63; Riddle, Christian Antiq. (see Index).