Addendum to my previous post
At the end of my last post, I speculated that Plutarch might indeed mean for us to take Gryllus’ arguments as sophistical, but as part of an attempt to bring us (the readers) to the realization that arguments for the superiority of humans over animals are equally sophistical. I think some further support for this view (toward which I am leaning more strongly now) comes from the fact that some techniques of sophistry are apparent in Gryllus’ arguments. For instance, Gryllus argues that sexuality in animals is more restrained than in humans: it is seasonal and aims at reproduction, and once that function is satisfied it goes away. They do not act in the licentious ways that humans act, and this shows that they are more temperate than humans. We certainly know now that this is hardly true of all non-human animals, and I think we can say the same of Plutarch: he deliberately has Gryllus selectively choose those examples that support his position, while ignoring entirely those that do not. The Cleverness of Animals, for instance, clearly shows that Plutarch was aware of divergence in the degree to which different animals possess different “virtues”. This selective use of examples is disingenuous on Gryllus’ part and I think it’s reasonable to say that Plutarch expects us to realize this—and then to notice how equally disingenuous are the efforts on the parts of those philosophers who rate the human so highly.
This, then, I think lends some further support to my closing speculation.