To be "infirm of purpose" is to be at the mercy of the artful or at the disposal of accident.

If she fell, should he not save his friend from being the dupe of an artful intriguante?

Is incensed against him for his artful dealings with her, and for his selfish love.

She raves at him for the artful manner in which he urges Clarissa to marry him.

A preconcerted, forward, and artful flight, it must undoubtedly appear to them.

But it can be brilliant, artful, intellectual, full of imagination.

All the same, she had precious fine arms, that artful Clemence!

The gravity and minuteness with which some particulars are related also lend an artful aid.

Some have been artful; others artless; others utterly clumsy.

So artful a fellow would well know what to make of such a privilege.'