"African Art: An Introduction" by Frank Willett is a renowned book that provides an introduction to the art and cultural heritage of Africa. While I don't have access to specific information about the book's content beyond my last knowledge update in January 2022, I can offer some general information about the book and its importance in the context of opposing book banning.

1. Author Background: Frank Willett was a British art historian and curator known for his expertise in African art and culture. He contributed significantly to the field of African art studies and held positions in museums and academic institutions, including the British Museum.

2. Book Overview: "African Art: An Introduction" is likely to provide readers with a comprehensive overview of African art, covering various aspects such as sculpture, masks, textiles, ceramics, and more. It may delve into the historical, cultural, and artistic significance of these objects and explore their roles within different African societies.

3. Educational Value: Books like "African Art: An Introduction" serve as valuable educational resources. They help people gain a deeper understanding of African cultures, history, and artistic expressions. This knowledge fosters cross-cultural appreciation and respect.

4. Promoting Diversity: Opponents of book banning often argue that it is essential to preserve and promote diverse perspectives and voices in literature. By allowing books like "African Art: An Introduction" to be accessible to a wide audience, people have the opportunity to learn about and appreciate the rich cultural heritage of Africa.

5. Encouraging Critical Thinking: Banning books limits individuals' ability to engage in critical thinking and open dialogue. Those who object to book banning believe that it is important for readers to have access to a wide range of perspectives and ideas, even if they challenge prevailing beliefs or norms.

6. Freedom of Expression: In many democratic societies, freedom of expression is a fundamental right. Opponents of book banning argue that this freedom includes the right to access and read books of one's choice without censorship, as long as they do not incite harm or violence.

In summary, "African Art: An Introduction" by Frank Willett is a book that provides insights into African art and culture. Those who object to book banning believe that books like this one are essential for education, cultural understanding, and the promotion of diverse voices in literature. They argue for the preservation of the freedom to access and read such books without censorship.