This is deceptively compelling. At first glance, the ape men, broken english, and doctrine that all animals converge on the perfect (evidently white) human form feels teleological with a distinct flavor of eugenics. But as the film progresses, it builds out a much more nuanced narrative. "Are we not men?" cry the islanders, taught this mantra by Moreau himself. But Moreau does not truly want them to see themselves as fully human. To him they are at their most compelling, and their most useful, as a sub-human who will do his bidding without ever being his equal.
Although Moreau's work isn't precisely secret, he is coy about it, and when he speaks to the mainland about the other inhabitants of his island he refers to them as "the natives". This gives away the allegory: Moreau is a colonizer and the beast-men his colonized subjects. Whatever he has given them has come with a terrible price: not just subservience but subhumanity. When Bela Lugosi's striking Speaker of the Law accuses Moreau of making them "not men but things", I hear it not as a tired admonishment to avoid meddling in the natural order, but as a claim that it is Moreau himself—despite his vaunted laws—who prevented them from becoming fully human.
It's telling that where H. G. Wells's novel is structured around the tendency of beast-men to revert to their bestial instinct, the film pushes this thread far into the background. The climax of the plot is no longer driven by instinctual violence, but by words: the Speaker of the Law confronts Moreau and declares his laws void because they are built on lies and hypocrisy. In their way, the beast-men are more rational than Moreau himself. The film ends by challenging the core dichotomy between "beast" and "man" at its root and suggesting (surprisingly deftly for a film made within Wells's lifetime) that the concept of "sub-humanity" is itself inhuman.