The battles between Michael Bakunin and Karl Marx in the First International began a pattern of polemics and rancor between anarchists and Marxists that still exists today. Outlining the profound similarities between Bakunin and Marx in their early lives and careers as activists, Mark Leier (author of Bakunin: The Creative Passion) suggests that the differences have often been exaggerated and have prevented activists from learning useful lessons about creating vibrant movements.