As a matter of fact, there is mixed opinion as to whether The Tenant of Wildfell Hall is or is not a classic literary work. A classical work of literature is generally defined by scholars as having to do with its value and its impact. A work might be said to be valuable if its themes are universal and timeless, such as the arrogance of human folly; the consequences of human error; etc. A work might be said to have an impact if it helps shape subsequent literary periods; if it reveals truth previously hidden; if it has one or more outstanding qualities or characteristics.
One opinion has it that if Charlotte Brontë had not been the executrix of Anne's literary estate, the book would not have gone out of print and out of literary history. It is said that its continuation, coupled with its strong popular reception, would have done much to win it a place as a literary classic.
Another opinion has it that the characterizations are unnatural and clumsy; that the talent is raw and ill-developed; that the story is dull and poorly written despite its moral and ethical virtues. Critics at the time of its publication and in subsequent eras have generally agreed about its deficiencies, especially in characterization, yet audiences have generally agreed that it is interesting by continuing to read it.
Based on the definition and these remarks, this book might be said to be classic on the basis of (1) impact, as it was a precursor to realism, and (2) enduring quality and devotion to the truth. According to critics, the book does what Anne Brontë wanted it to do: it tells the truth about abuses among men in the nineteenth century and about the violence between friends and in marriages.
My object in writing the following pages was ... [that] I wished to tell the truth, for truth always conveys its own moral to those who are able to receive it. But as the priceless treasure too frequently hides at the bottom of a well, it needs some courage to dive for it, especially as he that does so will be likely to incur more scorn and obloquy .... (Anne Brontë, Preface to the Second Edition)