To my thinking this is a profound error.

M.Zola has always remained faithful to himself.

The only difference that I perceive between his latest work, "Paris," and certain Rougon-Macquart volumes, is that with time, experience and assiduity, his genius has expanded and ripened, and that the hesitation, the groping for truth, so to say, which may be found in some of his earlier writings, has disappeared.
At the time when "The Fortune of the Rougons" was first published, none but the author himself can have imagined that the foundation-stone of one of the great literary monuments of the century had just been laid.
From the "story" point of view the book is one of M.Zola's very best, although its construction--particularly as regards the long interlude of the idyll of Miette and Silvere--is far from being perfect.

Such a work when first issued might well bring its author a measure of popularity, but it could hardly confer fame.

Nowadays, however, looking backward, and bearing in mind that one here has the genius of M.Zola's lifework, "The Fortune of the Rougons" becomes a book of exceptional interest and importance.