A major theme is the warlike nature of man. Critic Harold Bloom praised Blood Meridian as one of the best 20th century American novels, describing it as "worthy of Herman Melville's Moby-Dick," but admitted that he found the book's pervasive violence so distasteful that he had several false starts before reading the book entirely. Caryn James argued that the novel's violence was a "slap in the face" to modern readers cut off from the brutality of life, while Terrence Morgan thought that, though initially shocking, the effect of the violence gradually waned until the reader was bored. Billy J. Stratton contends that the brutality depicted is the primary mechanism through which McCarthy challenges binaries and promotes his revisionist agenda. Lilley argues that many critics struggle with the fact that McCarthy does not use violence for "jury-rigged, symbolic plot resolutions… In McCarthy's work, violence tends to be just that; it is not a sign or symbol of something else."
Epigraphs and ending
Three epigraphs open the book: quotations from French writer Paul Valéry, from German Christian mystic Jacob Boehme, and a 1982 news clipping from the Yuma Sun reporting the claim of members of an Ethiopian archeological excavation that a fossilized skull three hundred millennia old seemed to have been scalped. The themes implied by the epigraphs have been variously discussed without specific conclusions.
As noted above concerning the ending, the most common interpretation of the novel is that Holden kills the kid in a Fort Griffin, Texas outhouse. The fact that the kid's death is not depicted might be significant. Blood Meridian is a catalog of brutality, depicting, in sometimes explicit detail, all manner of violence, bloodshed, brutality and cruelty. For the dramatic climax to be left undepicted leaves something of a vacuum for the reader: knowing full well the horrors established in the past hundreds of pages, the kid's unstated fate might still be too awful to describe, and too much for the mind to fathom: the sight of the kid's fate leaves several witnesses stunned almost to silence; never in the book does any other character have this response to violence, again underlining the singularity of the kid's fate.
Patrick W. Shaw argues that Holden has sexually violated the protagonist. As Shaw writes, the novel had several times earlier established "a sequence of events that gives us ample information to visualize how Holden molests a child, then silences him with aggression." According to Shaw's argument, Holden's actions in the Fort Griffin outhouse are the culmination of what he desired decades earlier: to rape the kid, then perhaps kill him to silence the only survivor of the Glanton gang. If the judge wanted only to kill the kid, there would be no need for him to undress as he waited in the outhouse. Shaw writes,
When the judge assaults the kid in the Fort Griffin jakes… he betrays a complex of psychological, historical and sexual values of which the kid has no conscious awareness, but which are distinctly conveyed to the reader. Ultimately, it is the kid's personal humiliation which impacts the reader most tellingly. In the virile warrior culture which dominates that text and to which the reader has become acclimated, seduction into public homoeroticism is a dreadful fate. We do not see behind the outhouse door to know the details of the kid's corruption. It may be as simple as the embrace that we do witness or as violent as the sodomy implied by the judge's killing of the Indian children. The kid's powerful survival instinct perhaps suggests that he is a more willing participant than a victim. However, the degree of debasement and the extent of the kid's willingness are incidental. The public revelation of the act is what matters. Other men have observed the kid's humiliation… In such a male culture, public homoeroticism is untenable and it is this sudden revelation that horrifies the observers at Fort Griffin. No other act could offend their masculine sensibilities as the shock they display… This triumph over the kid is what the exhibitionist and homoerotic judge celebrates by dancing naked atop the wall, just as he did after assaulting the half-breed boy.—Patrick W. Shaw, "The Kid's Fate, the Judge's Guilt"
Yet Shaw’s effort to penetrate the mystery in the jakes has not managed to satisfy other critics, who have rejected his thesis as more sensational than textual:
Patrick W. Shaw's article . . . reviews the controversy over the end of McCarthy's masterpiece: does the judge kill the kid in the 'jakes' or does he merely sexually assault him? Shaw then goes on to review Eric Fromm's distinction between benign and malignant aggression – benign aggression being only used for survival and is rooted in human instinct, whereas malignant aggression is destructive and is based in human character. It is Shaw's thesis that McCarthy fully accepts and exemplifies Fromm's malignant aggression, which he sees as part of the human condition, and which we do well to heed, for without this acceptation we risk losing ourselves in intellectual and physical servitude. Shaw goes in for a certain amount of special pleading: the Comanches sodomizing their dying victims; the kid's exceptional aggression and ability, so that the judge could not have killed him that easily; the judge deriving more satisfaction from tormenting than from eliminating. Since the judge considers the kid has reserved some clemency in his soul, Shaw argues, that the only logical step is that the judge humiliates him by sodomy. This is possible, but unlikely. The judge gives one the impression, not so much of male potency, but of impotence. His mountainous, hairless flesh is more that of a eunuch than a man. Having suggested paedophilia, Shaw then goes back to read other episodes in terms of the judge's paedophilia: the hypothesis thus becomes the premise. And in so arguing, Shaw falls into the same trap of narrative closure for which he has been berating other critics. The point about Blood Meridian is that we do not know and we cannot know.—Peter J. Kitson (Ed.), "The Year's Work in English Studies Volume 78 (1997)"
Various discussions by Leo Daugherty, Barclay Owens, Harold Bloom and others, have resulted from the second epigraph of the three which are used by the author to introduce the novel taken from the Gnostic mystic Jacob Boehme. The quote from Boehme reads as follows: "It is not to be thought that the life of darkness is sunk in misery and lost as if in sorrowing. There is no sorrowing. For sorrow is a thing that is swallowed up in death, and death and dying are the very life of the darkness." No specific conclusions have been reached concerning its interpretation and the extent of its direct or indirect relevance to the novel.
These critics agree that there are Gnostic elements present in Blood Meridian, but they disagree on the precise meaning and implication of those elements. One of the most detailed of these arguments is made by Leo Daugherty in his 1992 article, "Blood Meridian as Gnostic Tragedy." Daugherty argues "Gnostic thought is central to Cormac McCarthy's Blood Meridian" (Daugherty, 122); specifically, the Persian-Zoroastrian-Manichean branch of Gnosticism. He describes the novel as a "rare coupling of Gnostic 'ideology' with the 'affect' of Hellenic tragedy by means of depicting how power works in the making and erasing of culture, and of what the human condition amounts to when a person opposes that power and thence gets introduced to fate."
Daugherty sees Holden as an archon, and the kid as a "failed pneuma." The novel's narrator explicitly states that the kid feels a "spark of the alien divine". Furthermore, the kid rarely initiates violence, usually doing so only when urged by others or in self-defense. Holden, however, speaks of his desire to dominate the earth and all who dwell on it, by any means: from outright violence to deception and trickery. He expresses his wish to become a "suzerain," one who "rules even when there are other rulers" and whose power overrides all others'. In 2009, Bloom did refer to Boehme in the context of Blood Meridian as, "a very specific type of Kabbalistic Gnostic".
Daugherty contends that the staggering violence of the novel can best be understood through a Gnostic lens. "Evil" as defined by the Gnostics was a far larger, more pervasive presence in human life than the rather tame and "domesticated" Satan most Christians believe in. As Daugherty writes, "For [Gnostics], evil was simply everything that is, with the exception of bits of spirit imprisoned here. And what they saw is what we see in the world of Blood Meridian." Barcley Owens argues that, while there are undoubtedly Gnostic qualities to the novel, Daugherty's arguments are "ultimately unsuccessful," because Daugherty fails to address the novel's pervasive violence adequately and because he overstates the kid's goodness.
Another major theme concerning Blood Meridian involves the subject of theodicy. Theodicy in general refers to the issue of the philosophical or theological attempt to justify the existence of that which is metaphysically or philosophically good in a world which contains so much apparent and manifest evil. Douglas Canfield in his essay "Theodicy in Blood Meridian" (in his book Mavericks on the Border, 2001, Lexington University Press) has made the assertion of the centrality of this theme throughout Blood Meridian. James Wood in his essay for The New Yorker entitled "Red Planet" from 2005 took a similar position to this in recognizing the issue of the general justification of metaphysical goodness in the presence of evil in the world as a recurrent theme in the novel. This was directly supported by Edwin Turner on 28 September 2010 in his essay on Blood Meridian for Biblioklept. Chris Dacus in the Cormac McCarthy Journal for 2009 wrote the essay entitled, "The West as Symbol of the Eschaton in Cormac McCarthy," where he expressed his preference for discussing the theme of theodicy in its eschatological terms in comparison to the theological scene of the last judgment. This preference for reading theodicy as an eschatological theme was further affirmed by Harold Bloom in his recurrent phrase of referring to the novel as "The Authentic Apocalyptic Novel."