Types of satire can also be classified according to the topics it deals with. From the earliest times, at least since the plays of Aristophanes, the primary topics of literary satire have been politics, religion and sex. This is partly because these are the most pressing problems that affect anybody living in a society, and partly because these topics are usually taboo. Among these, politics in the broader sense is considered the pre-eminent topic of satire. Satire which targets the clergy is a type of political satire, while religious satire is that which targets religious beliefs. Satire on sex may overlap with blue comedy, off-color humor and dick jokes.