H. G. Wells 
The New Machiavelli 

A successful author and Liberal MP with a loving and benevolent wife, Richard Remington appears to be a man to envy. But underneath his superficial contentment, he is far from happy with either his marriage or the politics of his party. The New Machiavelli describes the disarray into which his life is thrown, when he meets the young and beautiful Isabel Rivers and becomes tormented by desire. At first, he struggles to resist and remain focused upon his familiar political, personal and social life. But as he soon learns, it is harder than he could have imagined to turn his back on love.