1. Sentence Analysis:
2. Logical Sequence:
Sentences 1, 3, and 5 all address the concept of moral consideration for animals, focusing on their interests and our corresponding duties. Sentence 2 provides context for Peter Singer's utilitarian approach to animal rights, which supports this ethical argument. Sentence 4, however, solely discusses the historical impact of Singer's book, "Animal Liberation," as a landmark publication.
3. Conclusion:
Sentence 4 is centered on historical significance rather than developing the core argument about animal rights and moral duties. Therefore, Sentence 4 is the sentence that doesn't fit with the paragraph's primary focus on ethical arguments for animal rights.