Expressing all of this is a subtle architectural challenge, but this building meets it.

When Henry James shows us the world through such a character, the reader is rewarded with an extraordinarily subtle interpretive challenge.

There was always some degree of ironic amusement, cool detachment, or subtle challenge reflected there.

Brennan asked, meeting the subtle challenge of her tone and expression.

The 35-year-old Price has the kind of wrinkle-free golf swing that should endure as he gets a firmer grasp on the game's more subtle challenges.

But good times bring subtle but difficult challenges.

It is in some ways a grander mission, carrying a deep and subtle moral challenge.

George Bush has a more subtle challenge.

Moderators also deal with subtler challenges: they try to ensure that people posting messages have interesting conversations.

Balancing the dangers and rewards of childhood risk-taking is a subtle challenge.