The validity of bringing together the works of writers who may have little in common other than their religious allegiance is not something which could be justified in every age, especially within the current ecumenical climate. Two anthologies of Catholic poets, Shane Leslie's of 1925 and Frank Sheed's of 1943 may appear to today's reader rather more revelatory of the taste and beliefs of the compilers and their periods than of the poets concerned. Yet it can be claimed that scrutiny of the religious poetry of Catholic writers of the first half of the seventeenth century has a validity which might be lacking in a later period. If religious poetry is indeed the expression of sincere conviction, it is to be expected that writers who have different beliefs will differ also in the forms of expression they give to them in their poetry. In the light of this, the question may be asked as to how, in the seventeenth century, the religious poetry written by Catholics differs from that written by Protestants. The study of a large number of minor writers of this period leads to the conclusion that in the seventeenth century the choice and treatment of subject matter seems to be more integrally related to religious conviction than is the case in later periods.