"We are moving too slow," he said in 1989, repeating a frequent theme.

The most frequent themes are loneliness, age, love, death, physics and religion.

Our departure for the woods became now a frequent theme of conversation.

Apocalypticism is a frequent theme of literature, film and television.

The intersection of art and science is a frequent theme among younger artists.

A frequent theme his novels explore is the conflict between good and evil.

The importance of history, community, art, and imagination have been frequent themes in his work.

Symbols of human suffering were a frequent theme in his work.

With the human body a frequent theme, though, some works here are decidedly more disturbing.

Life's dangers were a frequent theme of 19th-century Australian children's fiction.