Dr. Moreau is a genius, gifted with a knowledge of science and the skills to back it up. Unfortunately, his insane pursuit of scientific perfection leads him to bend the law—and common decency—enough for him to be run out of London town. So, he sets up shop on some remote island and starts getting to work creating monsters for some reason or another. He's exactly one hunchback away from being nominated as president of the European chapter of the Mad Scientist League.
Part of the reason London town gave Moreau the boot was because his experiments involved vivisection. What's vivisection, you ask? Well, vivisection is the process by which a scientist autopsies and experiments on an animal while it is still alive. Painkillers optional. The whole thing is just as unpleasant as it sounds.
In Moreau's case, he used the process to create a race of creatures shaped like man-beast hybrids called the Beast Folk, making things even more unpleasant. (If you want to learn more on vivisection, jump over to our "Symbols, Imagery, Allegory" section.)
But why is he creating the Beast Folk, exactly? Victor Frankenstein had much clearer motivations for creating his monster. That may be true, and Moreau's reasons can certainly be mysterious, but he does tell Prendick a bit about why he does what he does.
During their discussion, Moreau mentions he is seeking the laws of God (14.26). But later in the discussion, Moreau admits, "[…] everything I do that defeats me, makes me dissatisfied, challenges me to further effort. Sometimes I rise above my level, sometimes I fall before it, but always I fall short of the things I dream" (14.42). While he may be seeking God's laws, it seems he's also trying to reach God's level, the ability to craft life and nature to his will. In short, he has a god complex and wants the world to be his personal version of SimCity. Speaking of which…
Moreau neither hates nor loves the Beast Folk. He's mostly indifferent to them. Their existence only "sicken[s] [him] with a sense of failure" (14.47). When he has finished working on one, he releases it from the House of Pain, and whether it finds its way to the other Beast Folk is none of his concern. He is, in a word, a jerk.
He does interact with the Beast Folk on occasion but as their God. He comes to them only when one has broken the Law and then returns that creature to the House of Pain where he works on them until they are sufficiently human again. Here, Moreau's God acts less like the benevolent God of Christian mythology and more like an act of nature. In his own words, he is "remorseless" (14.29). His only goal is to work out the imperfections he sees as failures reflecting on his skill. The benefit of the beast person in question is of no concern.
In this light, Moreau as a God seems to mix with the process of evolution. In him, these two seemingly opposing ideas find a sort of middle ground although the result is hardly what one would call comforting.
It's fitting then that Moreau's own experiment kills him. Harsh, we know, but true. When the puma escapes from the enclosure, Moreau chases after him. In an unseen scuffle, the two bring each other to their own demises. The Beast Folk are left without their God, and when Prendick burns down the enclosure, they lose their Hell too. Wow, that's one heck of a day.
Considering their God was a divine jerk, you'd think it would be happy days and rainbows from here on out. But hold onto that thought, because the Beast Folk mostly go on as before. They eat, they drink, and some of them break the Law and do violence to one another. Some doubt the Law still exists and others remain fervent followers. Eventually, without Moreau, they revert back to their animal selves.
This leads to a very ambiguous understanding of Moreau. On the one hand, he causes pain and suffering for the Beast Folk. On the other hand, the Beast Folk seem to cause plenty of pain and suffering for each other, without Moreau's help. In fact, when Prendick and company go to pick up Moreau's body, they are attacked by "a feral monster in headlong pursuit, blood-bedabbled, […]" (18.28). Moreau's body is barely cold, and the Beast Folk are already trying to kill each other.
What was Moreau's influence on the island in the end? Did he change the Beast Folk for the better? For worse? Despite all the pain, did he really even change anything at all?