Texts make various different types of demands on the reader. Some are densely written and philosophically complex. Others contain many moral ambiguities and challenge the reader's way of looking at the world. Still more contain a plethora of unfamiliar words and phrases. Many have all three of these types of difficulty, and more besides.

Tom Jones was published in 1749. It is probably reasonable to say that any book written so long ago is too remote from our culture to be entirely straightforward. On every page, the reader finds unfamiliar social attitudes and assumptions. These are accompanied by demands of a more basic linguistic nature. Take the very first sentence of the book:

An author ought to consider himself, not as a gentleman who gives a private or eleemosynary treat, but rather as one who keeps a public ordinary, at which all persons are welcome for their money.

If the reader does not need to look up the word "eleemosynary" (which means "charitable") then they have a better vocabulary than most. If they guess the meaning of the phrase "public ordinary," it is only from the context, not because they is accustomed to encountering the word "ordinary" as a noun. There are plenty of much longer sentences in the ensuing narrative that present far more difficulties than this. While it is true that the book is not morally or philosophically complex, its polysyllabic humor, long digressions, and cultural remoteness can be demanding even for highly sophisticated readers, particularly if they are not already familiar with eighteenth-century prose.