The unified story of humankind that long dominated how people thought of the past, present, and future is known as

Grand narrative.

Explanation:

As the exercise briefly states, the unified story of humankind that long dominated how people thought of the past, present, and future is known as grand narrative. This grand narrative is a post-modern thesis about meta narratives, which brought skepticism given that constructing grand theories leaves out the picture the natural and existing chaos and disorder of the individual event.

answer; pluralist democracy;

answer; c.wright mills;