In the modern world, there is no escape from sex: we are bombarded by role models and advice on intimate relationships. Sexual imagery sells and it is now everywhere. The Introduction looks at the culture of sex today. In modernity, we freely define ourselves through our sexuality to try to make sense of who we are. This is a 20th-century development. Sex is a cultural object: the ways in which different cultures and time periods have made sense of the erotic vary widely. Sexuality today is shaped by social and political forces and is connected in different ways to power, class, race, and gender.