The first chapter presents Animism as a coherent foundational principle for environmental philosophy. Beginning with an examination of what spirit means to indigenous people, I offer a revision of classical animism, called "global animism". Three general principles constitute global animism: motion and transience, energy and connectivity, and a global life-seeking purposiveness, called The Will to Life. The second chapter explores how the Will to Life can mistake itself. Parasitism is the Will to Life in self-negating pathological disorder. Certain human activities must be characterized as parasitism, because of their destructiveness. An "activist sequence" explains why environmental activism, including and especially radical and confrontational activism, is a needed force to halt the destruction of the environment. Finally, a guiding ethical principle called the "activists' imperative" argues that we are called upon to disobey the demands of disordered social institutions. The environmental activist is a catalyst for the rectification of the disordered Will to Life.