Academics have noted how the Dominion War plotlines have explored the human psyche as much as outer space. Lincoln Geraghty praises the ending to the story arc and "" as a series, and believes this is indicative of how the series manipulates the "Star Trek" ethos, identifying a theme of ambiguity as part of its continuing narrative. Karin Blair, writing in 1997 at the time of Season Five, felt that the series was reflecting trends for American culture to re-consider its place in the global community. Michele and Duncan Barrett comment on the "declining faith in rationalism that haunts "Deep Space Nine"" in their book "Star Trek: The Human Frontier".