 Here is a first, simple definition. Pornography is any material (either pictures or words) that is sexually explicit. This definition of pornography may pick out different types of material in different contexts, since what is viewed as sexually explicit can vary from culture to culture and over time. “Sexually explicit” functions as a kind of indexical term, picking out different features depending on what has certain effects or breaks certain taboos in different contexts and cultures. Displays of women’s uncovered ankles count as sexually explicit in some cultures, but not in most western cultures nowadays (although they once did: the display of a female ankle in Victorian times was regarded as most risqué). There may be borderline cases too: do displays of bared breasts still count as sexually explicit in various contemporary western cultures? However, some material seems clearly to count as sexually explicit in many contexts today: in particular, audio, written or visual representations of sexual acts (e.g., sexual intercourse, oral sex) and exposed body parts (e.g., the vagina, anus and penis-especially the erect penis).