"A book is simply the container of an idea like a bottle; what is inside the book is what matters"

This quote by Angela Carter is a metaphor for the value of the material of a book. She is suggesting that the book itself is merely a vessel, like a bottle, and what is inside the book is what is genuinely important. This might be translated as a suggestion to focus on the compound of a book, rather than its physical type. Carter is highlighting the importance of the ideas and stories consisted of within a book, rather than the book itself. This quote might likewise be analyzed as a suggestion to focus on the content of any form of communication, instead of the form itself. Carter is suggesting that the concepts and stories consisted of within a book are what truly matters, which the physical form of the book is secondary.