Brisbois, Michael J. “Tolkien’s Imaginary Nature: An Analysis of the Structure of Middle-earth.” Tolkien Studies 2 (2005): 197-216. A semi-systematic examination of differing aspects of and relations to “nature” in Tolkien’s legendarium. Interesting topic with great potential, but somewhat imperfectly executed here. Summary of Randall Helm’s five “internal laws” is interesting and helpful, but Brisbois’s categories of Passive, Active, Essential, Ambient, Independent, and Wrathful seem to obscure as much as they reveal.