In this expanded edition, Singer supplements the 2001 edition with a timely and stimulating essay that focuses upon marriage, particularly same-sex marriage. Singer maintains that questions about sex are fundamental in all thinking about the marital condition, and addresses the problem of same-sex legitimization and rights to material benefits by analyzing the nature of marriage, union, and family in their relation to sexuality and love. For first-time and seasoned readers alike, Singer's lucid new reflections will clarify current and emerging issues in the philosophy of sex.