Who is Pisarev, Bakunin, Nechaiev from The Rebel and what is their importance?

Pisarev, Bakunin, Nechaiev were Russian philosophers, who were at the forefront in the development of Russian revolutionary thinking. Pisarev was a leader in the movement that added egoism; Bakunin immersed himself in Hegel, and as a result positioned himself on the side of constant, justified rebellion with the goal of creating "a new world, without laws, and consequently free"; Nechaiev, according to the author, "pushed nihilism to the farthest coherent point" by advocating pure revolution which was, to Nechaiev, "more important than the people it wanted to save..."