"I think I can see how the higher animals are in a sense drawn into Man when he loves them"

This reference to "higher animals" is a tipoff to Lewis's bias toward evolution, which he discusses in greater detail in chapter 11, "The New Men." Such a statement assumes that more apparently complex animals (e.g., vertebrates) evolved from less apparently complex or more primitive animals (e.g., nonvertebrates). Here's an article from Science Daily that questions that theory.

Evolution would postulate that man is the highest animal (although Lewis's statement here does not imply this); this idea contradicts a literal reading of the first three chapters of Genesis and is disputed by creationists.