I see the interaction between art and nature, as Bettina wrote about the gardens of Pemberley. This goes hand-in-hand with the deception theme I have focused on: are people being "real" or are they using "art and allurements" to get what they want. I also see the heart/head distinction you make, and the continuum in the Bennet family.

What I question is the identification of the heart with nature and the head with art. Is reason artful, something that has to be learned? I would say rather that following one's passions to the exclusion of reason is animalistic, while governing them properly with reason is human. I hope this isn't off topic. I'd like to know more about the medieval origins of this anithesis to understand it better, because I'm not quite sure the way you present it in your post is really the way JA is looking at it.