From Tom Jones, Book V, ch. i

Peradventure there may be no parts in this prodigious work which will give the reader less pleasure in the perusing than those which have given the author the greatest pains in composing. Among these probably may be reckoned those initial essays which we have prefixed to the historical matter contained in every book; and which we have determined to be essentially necessary to this kind of writing, of which we have set ourselves at the head.