The Island of Dr. Moreau
How we cite our quotes:
I say luckily for us he did not reach us, and I might also add luckily for himself, for there [was] only a small beaker of water and some soddened ship's biscuits with us […]. (1.3)
Put any person in an extreme situation, and our primitive side will show. Prendick tries to be reasonable about being lucky that a man died, and maybe he's right. Still, you've got to admit, that's pretty cold. Primitive and coldblooded.
The black hesitated before them, and this gave the red-haired man time to come up with him and deliver a tremendous blow between the shoulder-blades. (3.14)
M'ling is a Beast Folk and supposedly more primitive than a tried-and-true human. So, it's interesting that the primal act in this scene is performed by the oh-so pleasant Captain Davis.
I refused to go aboard her, and flung myself full-length on the deck. In the end they swung me into her by a rope—for they had no stern ladder—and cut me adrift. (5.25)
In theory, civilization has rules, and by following them, we'll stay civilized instead of primitive. However, Davis's men are only following the rules, but we'd qualify trying to throw a man into the middle of the Pacific a pretty weak thing to do. Guess it's less about just following rules and more about which rules to follow.