Full Idea
Women now have more control over becoming pregnant. Men can now be more certain of paternity, without the constraint of female chastity. Hence chastity is no longer considered a moral virtue.
Gist of Idea
Control of pregnancy and knowledge of paternity have downgraded chastity
Source
Julia Driver (The Virtues and Human Nature [1996], 5)
Book Reference
'How Should One Live? On the Virtues', ed/tr. Crisp,Roger [OUP 1998], p.126
A Reaction
A persuasive argument that virtues are defined by their consequences (to which I add my example of gossiping in wartime). Different social situations and crises promote or relegate the status of certain virtues (such as food hoarding).