" Texts are not immutable, or else adherents to the world's religions would have single interpretations of their content."

You have just stated the fallacy of you position. The text IS immutable. The text is, as the author wrote it. The worlds religions differ because MAN decides to alter what a religious text states; either to further their position, or because they disagree with it. Sucks to be them, sucks to be you, the words on the page are not mutable. This is why I consider the entire though process behind "I can claim whatever meaning I can plausibly fabricate, because the author is dead and can not refute me." moral and intelectual cowardice.

The text, is the text, is the text. It is what it is, & only what it is. It means what the author wrote. I shall prove it to you:

"The walls of my room are white."

now hit the back button on your commputer and then come to this page again (thank you for the second view ). Did the words change? Does the phrase above now state "I am afraid of individuals of Affrican decent"? Do they now read "Any room but mine is evil"? No they do not. They do not change, thus they are immutable. Your interpretation of them, as other than what they state, tell us nothing about the phrase (or a novel) only about you.

A critique would involve a discussion about how well the author conveyed his/her message. A review would tell how enjoyable receiving that message was. As for the immutable "truth" of the book, the author is on record about it already, I am not the source of it.

As for your definition of Ecology, yes it is semanticaly accurate; though coloqually archaic. By that definition ALL books have an "ecology" therefore all books are ecological. Therefore the labeling of Dune as an Ecological book would be both correct and completely pointless. A definition that broad, defines nothing, because it defines everything.