To Dante, Nature’s author is God himself and thus anything described as natural must honor the Divine. Thus, the most unnatural scenes occur in the circles of heresy and violence, where familiar or pastoral landscapes become distorted in some fundamental way. The violent, especially those who have sinned against nature, demonstrate this best – in the image of reproduction. Usurers gain from the unnaturally speedy accumulation of money, which requires no coupling but simply produces more and more in and of itself. Sodomites, on the other hand, engage in sexual practices that cannot possibly yield a child; they are the incarnation of sterility. Similarly, heretics, in denying man’s immortal soul, reject one of the basic truths. Heresy and violence are considered worse sins than incontinence. Where the incontinent are weak victims of their emotions, the heretics and violent willfully warp the natural order.
To support the idea that violent sinners move against the natural order, the environs of the Seventh Circle feature natural settings perverted in one fundamental aspect.
All of the guardians in the Seventh Circle juxtapose the bodies of two different species to reflect the perverted nature of the sinners.