Final answer:
According to Terence Thornberry, social change is a dynamic process reflecting the evolving nature of an ever-changing society, influenced by both internal movements and external factors.
Step-by-step explanation:
According to Terence Thornberry, social change is a function of a dynamic social process that changes over time. Social change reflects the evolving nature of society and can be influenced by factors such as social movements, technological advancements, and environmental shifts, leading to altered social structures and functions. The structural-functional theory, often tied to the work of sociologists like Émile Durkheim and Alfred Radcliff-Brown, suggests that various parts of society work together to maintain stability, a concept known as dynamic equilibrium. However, this theory has been criticized for its inability to explain social change sufficiently, as it often focuses on the stability and continuity of society's structures.