Right hand and successor to Dwight Lansford as de facto head of the Naturalist movement, Gunlar Debthey's strident tone, populist style and paramilitary leanings transformed the Naturalists from a group of scattered fringe academics and pacifist separatists into an insurgent political phenomenon. His accomplishments as the movement's head included the establishment of the Light of Reason militia and the successful campaign for the Year of Prohibition.

While Debthey's official rank within Lansford's Popular Society of Nature was Chief Science Advisor (elevated to People's Science Advisor after Lansford's death), he had no formal scientific education and viewed learning with suspicion. Indeed, Debthey is often criticized for taking the Naturalist movement away from a tradition of scientific rigor and slanting it more in the direction of lengthy paeans to the purity of the wind goddess. Nevertheless, Debthey's combination of flowery prose and fiery rhetoric won over crowds by the thousands and turned the movement into one that was impossible to ignore - especially for the lone engineers frequently torn to shreds by mobs after a major Debthey gathering.

Debthey was famously antagonistic towards rival theorists of aether-damage, especially Josephine Tredimus, who maintained that Dead Air was caused by Gravitopolis's infamous Worldmachine, and the Harmonists, who believed that natural laws governing the aether were but the first to be overwritten by hostile physics from the Zone of High Matter. It was Debthey's hatred of the latter that led him to direct the assasination of the Harmonist Puloto Elder Omana Tann, triggering the disaster of the Little War and ultimately the demise of the Naturalist movement itself.

As a military leader Debthey was better than average but no tactical genius, and ill-suited to launching the Naturalists into a full-scale military conflict. While the Light of Reason was fairly accomplished in the use of jump-and-glide tactics and in the use of improvised Cloudstone bombs, their refusal to use post-Convection Engine flight tech made them hopelessly outgunned. What they did have, however, was a mass of public support - support which swiftly burnt out over the years of the bloody conflict. By the time Debthey's body was discovered in one of the last of the Naturalist bunkers at the close of the war - an apparent suicide - none of his followers remained to claim or bury it.

—Rudgaard Vanderplast