He could have been talking about the theme of his new book.

The general theme of the book is the relationship between politics and philosophy.

Yet, in a sense, that becomes the theme of the book.

The principal theme of the book and play is that man has the free will to change his image.

A main theme of the book is the struggle between good and evil.

The overall theme of the book is thus individual and social change being provoked by strong outside forces.

Another theme of the book is what happens to human skills as the population decreases.

The central themes of the book are equally if not more relevant today.

But the insidious theme of the book is his alone.

The book's peripheral characters play an important part in the general theme of the book.