Hybrids, as horticulturists know, sometimes produce the most brilliant blossoms in the garden. Hybridization in human culture, particularly in the arts, can also have memorable results. Anglo-Irish writing, from Maria Edgeworth to William Trevor, has been one of the glories of literary art; but the term “Anglo-Irish” can be confusing, because it is sometimes applied to all literature in English by Irish writers—as distinguished from literature in the Irish language, which is considerable.

Julian Moynahan, in his comprehensive and satisfyingly readable study subtitled “The Literary Imagination in a Hyphenated Culture,” defines his subject as follows: “Anglo-Irish literature is the writing produced by that ascendant minority in Ireland, largely but not entirely English in point of origin, that tended to be Protestant and overwhelmingly loyal to the English crown, and had its power and privileges secured by the English civil and military presence.” In political and economic terms the Protestant Ascendancy’s golden age came during the last decades of the eighteenth century, when the Irish Parliament asserted its power as an independent governing body. This coincided with an inspired building boom which made Dublin one of the great Georgian capitals in Europe.

“Something shattering would have to happen,” Moynahan writes, “to awaken the Ascendancy to reality and to show its members how they actually stood toward the English and toward their fellow-Irish before a genuine Anglo-Irish literature . . . could get under way.” With almost uncanny timing the first demonstrably Anglo-Irish novel, Castle Rackrentby Maria Edgeworth,