She seemed to grow gayer and more brilliant in his presence.
The most futile thing in this world is any attempt, perhaps, at exact definition of character.

All individuals are a bundle of contradictions--none more so than the most capable.
In the case of Aileen Butler it would be quite impossible to give an exact definition.

Intelligence, of a raw, crude order she had certainly--also a native force, tamed somewhat by the doctrines and conventions of current society, still showed clear at times in an elemental and not entirely unattractive way.

At this time she was only eighteen years of age--decidedly attractive from the point of view of a man of Frank Cowperwood's temperament.

She supplied something he had not previously known or consciously craved.