Transhumanists would have humanity's creation of posthumanity be our governing aim. Susan B. Levin challenges their overarching commitments regarding the mind, brain, ethics, liberal democracy, knowledge, and reality. Her critique unmasks their notion of humanity's self-transcendence via science and technology as pure, albeit seductive, fantasy. Global pandemics, climate change, looming geopolitical conflicts over fresh water and food--it seems the more we should learn how to change the behavior of humans in nature, the more we recoil and try to find a way out by changing nature in humans instead. One such recoil is transhumanism. Posthuman Bliss? offers a searching critique of biotechnical fabrication of human thought and emotion on the molecular level. Welcome to bioethical thinking that is critical, not apologetic. Welcome to classical philosopher Susan B. Levin's interdisciplinary perspective on the limits of biopower.