Anthropocene reflections on evil demand renewed engagement with religious and philosophical accounts. Classical falsafa—the Islamic adaptation of Hellenistic philosophy—typically denies evil's real existence, viewing the world as necessarily optimal and evil as a mere privation of good. This deterministic model complicates issues of divine justice, free will, and moral responsibility—concerns central to addressing human-induced environmental destruction. Conversely, the Maktab-i Tafkīk (School of Separation) and its founder, Mīrzā Mahdī Iṣfahānī (d. 1365/1946), challenge these assumptions, rejecting the metaphysical grounds and moral implications of the philosophical tradition. Iṣfahānī replaces deterministic agency with a libertarian account for both divine and non-divine agents, grounded in rational intuition. He argues that the dominant philosophical view contradicts the foundations of prophecy, sharīʿa, and the afterlife by undermining moral responsibility. By distinguishing between justified and unjustified evils, Iṣfahānī maintains that both possess real existence. He posits that while God's moral character ensures He does not create evil without sufficient reason, humans remain fully accountable for the unjustified evils arising from the deliberate misuse of their free will. This paper examines Iṣfahānī's onto-epistemological framework in contrast with dominant Islamic perspectives. I argue that his emphasis on human freedom and the reality of unjustified evil offers vital resources for rethinking responsibility for ecological degradation and suffering in the Anthropocene. By framing environmental crises as "unjustified evils" born of human agency, Iṣfahānī's framework provides a robust ethical basis for accountability. This study highlights an Islamic reconceptualisation of evil that preserves divine justice without diminishing the ethical stakes of human action, addressing the urgent demands of our modern ecological crisis.