The aim of this paper is to take a close look at John McGahern’s mind style through the language of the heroine Elizabeth Reegan and other characters, in his 1963 novel The Barracks . Specifically, attention will be drawn to how the linguistic choices shape the figurative language to cast the author’s controversial views on the religion-pervaded puritan Irish society that he knew so well. This will be done from two different perspectives. One perspective is through the breast cancer afflicted heroine, who asserts herself as a free thinker and a woman of science, in a society where priests have a strong influence at all social levels, and most women settle for housekeeping. The other is also through Elizabeth, together with other minor characters, who dare question some of the basic well-established ideological assumptions, in a series of examples where the author skilfully raises two parallel dichotomies, namely, FAITH versus REASON, and DARKNESS versus LIGHT. At a linguistic level, the present analysis relies on precepts from Frame Semantics, Conceptual Metaphor Theory, and Cognitive Grammar. These insights prove a most useful method of approach to a narrative text while unearthing the author’s ideological world view.