Chivalry makes a comeback; The Return to Camelot: Chivalry and the English Gentleman, by Mark Girouard. New Haven, Conn.: Yale University Press. 320 pp. $35.

March 12, 1982

Most people today would be hard put to identify a ''gentleman.'' Models of courtesy, honesty, and selflessness have waned to the extent that their practitioners are suspect, and the teen-age archetype is no longer a Boy Scout.

If you find this a regrettable state of affairs, you'll enjoy ''The Return to Camelot,'' a study of how medieval chivalry was reinstituted in early 19 th-century England. Mark Girouard, an English architectural historian, has produced a well-documented, beautifully illustrated book explaining how the Victorian English gentleman grew out of the myth of King Arthur and his honorable knights. Girouard does not neglect to point out the ridiculous aspects of the return to chivalry, even as he illuminates the influential rules of the game.

The chivalric concept - defense of church and the wrongfully oppressed, death before dishonor - had disappeared (if indeed it ever was more than a myth) by the Age of Enlightenment. Eighteenth-century England - with its scientific discoveries, its paid professional soldiers, its rising business class - caused Edmund Burke to write, ''The age of chivalry is gone.''

He was premature. Into the democratic materialism of the Industrial Revolution leaped a group of idiosyncratic writers, architects, and painters waiting to lead a charge toward a new movement. They encouraged their countrymen to become latter-day knights and chivalrous gentlemen, replete with everything but the suits of armor. Sir Walter Scott, Tennyson, Landseer, and Disraeli, among others, defined ''gentleman'' to the world - brave, loyal, true to his word, courteous, generous, and merciful. Of course this romantic concept had many flaws, and Mr. Girouard is honest about them. The code of chivalry was elitist, Christian, and sexist. It glorified war.

The enemy of chivalry was the middle class. The middle class used the word ''democracy'' as a standard to support universal suffrage, trade unions, cheap newspapers, and education without religion. These ideas met with the scorn of the knights, causing one, Kenelm Digby, to write that ''democracy was utterly opposed to all the principles of the ancient as well as of the Christian chivalry.''

So, the demos were kept out of the moral world of 19th-century chivalry. But ethnics and the working class were permitted to enter, and many did. They were encouraged by such organizations as Lord Baden-Powell's Boy Scouts, the Boys' Brigade, and the Jewish Lads' Brigade. But even the lower classes were never allowed to forget that their role models were the privileged of birth and education and that standards were set by the confines of Christianity. ''Real gentlemen'' and ''natural gentlemen'' were separate and unequal.

Women and sex were given short shrift too. Both existed, of course, even the revivified knights couldn't deny that, but more spiritually than physically. The Victorian woman was elevated to a queenly position, and her crown was courtly love, not eroticism. There was no provision for feminism in the chivalric code.

Since the training ground of Victorian and Edwardian chivalry was the public (private) British school system, the future leaders of the Empire and the homeland were graduates of the likes of Eton, Rugby, Harrow, and Marlborough - exclusive bastions of upper-class maledom, usually. Character was ranked over intellect, sportsmanship over winning. Team spirit, leadership, and good fellowship were drilled unceasingly into the minds and hearts of the public-school boys, as well as absolute standards of good, right, and beauty.

Yet, the English gentleman's code of honor was by no means only empty gesture and moral posturing. As imperialism spread its tentacles, it sent out brave leaders who functioned with the same self-control under the broiling sun of the Sudan as they had on the playing fields of Eton. They were a principled elite, who set about to civilize the world, and almost succeeded. And the literature that sprang from the passion of chivalry has delighted millions of all ages - ''Ivanhoe,'' Tennyson's ''Idylls,'' the heroic poetry of World War I, to name a few examples. The lavish illustrations in ''The Return To Camelot'' demonstrate the architecture, portraiture, sculpture - some first-rate - that were created to coincide with the ideal.

Mr. Girouard says chivalry died in the trenches of World War I, where the carnage of bloody battles made chivalry irrelevant. Eight and one-half million died, and the world changed. Perhaps he is wrong in saying that the essential core of chivalry - high standards - is dead. Perhaps it is just dormant, preparing for a renewal with modern adaptations. If so, and even if not, ''The Return to Camelot'' is an excellent primer.