The discipline of anthropology is centered on the concept of culture. What we make, what we do, and what we think constitute the basic elements of culture. These elements combine in aggregates such as symbols, rituals, and social structures. Since the 19th century, anthropologists have developed various modes of analysis for understanding culture, some examining change over time and others considering the functions of culture at one particular point in time. While it is an incredibly useful tool for understanding human social life, the concept of culture is riddled with paradox. Though durable and integrated, culture is subject to constant change, mobility, contest, and variability.